fix: reordered init to suppress warnings and unit-conversion fix

src/blender_maxwell/node_trees/maxwell_sim_nodes/contracts/flow_kinds/params.py

@@ -56,6 +56,7 @@ class ParamsFlow:
 			msg = f"Symbols in {symbol_values} don't perfectly match the ParamsFlow symbols {self.symbols}"
 			raise ValueError(msg)
 
+		## TODO: MutableDenseMatrix causes error with 'in' check bc it isn't hashable.
 		return [
 			spux.scale_to_unit_system(arg, unit_system, use_jax_array=True)
 			if arg not in symbol_values

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/analysis/math/operate_math.py

@@ -30,6 +30,7 @@ from ... import base, events
 log = logger.get(__name__)
 
 FUNCS = {
+	# Number | Number
 	'ADD': lambda exprs: exprs[0] + exprs[1],
 	'SUB': lambda exprs: exprs[0] - exprs[1],
 	'MUL': lambda exprs: exprs[0] * exprs[1],

src/blender_maxwell/node_trees/maxwell_sim_nodes/nodes/base.py

@@ -974,16 +974,19 @@ class MaxwellSimNode(bpy.types.Node, bl_instance.BLInstance):
 		Notes:
 			Run by Blender when a new instance of a node is added to a tree.
 		"""
-		# Initialize Sockets
-		## -> Ensures the availability of static sockets before items/methods.
-		## -> Ensures the availability of static sockets before items/methods.
-		self._sync_sockets()
-
 		# Initialize Instance ID
 		## -> This is used by various caches from 'bl_cache'.
 		## -> Also generates (first-time) the various enums.
 		self.reset_instance_id()
 
+		# Initialize Sockets
+		## -> Ensures the availability of static sockets before dynamic fields.
+		self._sync_sockets()
+
+		# Initialize Dynamic Field Persistance
+		## -> Ensures the availability of enum items for subsequent setters.
+		self.regenerate_dynamic_field_persistance()
+
 		# Initialize Name
 		## -> Ensures the availability of sim_node_name immediately.
 		self.sim_node_name = self.name

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/base.py

@@ -51,6 +51,7 @@ class SocketDef(pyd.BaseModel, abc.ABC):
 			bl_socket: The Blender node socket to alter using data from this SocketDef.
 		"""
 		bl_socket.reset_instance_id()
+		bl_socket.regenerate_dynamic_field_persistance()
 
 	def postinit(self, bl_socket: bpy.types.NodeSocket) -> None:
 		"""Pre-initialize a real Blender node socket from this socket definition.
@@ -205,11 +206,12 @@ class MaxwellSimSocket(bpy.types.NodeSocket, bl_instance.BLInstance):
 		"""
 		## TODO: Evaluate this properly
 		if self.is_initializing:
-			log.debug(
-				'%s: Rejected on_prop_changed("%s") while initializing',
-				self.bl_label,
-				prop_name,
-			)
+			pass
+			# log.debug(
+			# '%s: Rejected on_prop_changed("%s") while initializing',
+			# self.bl_label,
+			# prop_name,
+			# )
 		elif hasattr(self, prop_name):
 			# Property Callbacks: Active Kind
 			if prop_name == 'active_kind':

src/blender_maxwell/node_trees/maxwell_sim_nodes/sockets/expr.py

@@ -214,9 +214,7 @@ class ExprBLSocket(base.MaxwellSimSocket):
 
 		return None
 
-	@bl_cache.cached_bl_property()
-	def prev_unit(self) -> spux.Unit | None:
-		return self.unit
+	prev_unit: str | None = bl_cache.BLField(None)
 
 	####################
 	# - Prop-Change Callback
@@ -231,19 +229,21 @@ class ExprBLSocket(base.MaxwellSimSocket):
 			## -> 1. "Laggy" unit must be different than new unit.
 			## -> 2. Unit-conversion of value only within same physical_type
 			## -> 3. Never unit-convert expressions w/symbolic variables
-			## No matter what, prev_unit is always re-armed.
+			## No matter what, prev_unit is always regenerated.
+			prev_unit = (
+				spux.unit_str_to_unit(self.prev_unit)
+				if self.prev_unit is not None
+				else None
+			)
 			if (
-				self.prev_unit != self.unit
-				and self.prev_unit in self.physical_type.valid_units
+				prev_unit != self.unit
+				and prev_unit in self.physical_type.valid_units
 				and not self.symbols
 			):
-				log.critical(self.value, self.prev_unit, self.unit)
-				self.value = spu.convert_to(self.value, self.prev_unit)
-				log.critical(self.value, self.prev_unit, self.unit)
-				self.lazy_array_range = self.lazy_array_range.rescale_to_unit(
-					self.prev_unit
-				)
-			self.prev_unit = bl_cache.Signal.InvalidateCache
+				self.value = self.value.subs({self.unit: prev_unit})
+				self.lazy_array_range = self.lazy_array_range.correct_unit(prev_unit)
+
+			self.prev_unit = self.active_unit
 
 	####################
 	# - Value Utilities
@@ -378,18 +378,22 @@ class ExprBLSocket(base.MaxwellSimSocket):
 				),
 			},
 			NS.Vec2: {
-				MT_Z: lambda: sp.Matrix([Z(i) for i in self.raw_value_int2]),
-				MT_Q: lambda: sp.Matrix([Q(q[0], q[1]) for q in self.raw_value_rat2]),
-				MT_R: lambda: sp.Matrix([R(r) for r in self.raw_value_float2]),
-				MT_C: lambda: sp.Matrix(
+				MT_Z: lambda: sp.ImmutableMatrix([Z(i) for i in self.raw_value_int2]),
+				MT_Q: lambda: sp.ImmutableMatrix(
+					[Q(q[0], q[1]) for q in self.raw_value_rat2]
+				),
+				MT_R: lambda: sp.ImmutableMatrix([R(r) for r in self.raw_value_float2]),
+				MT_C: lambda: sp.ImmutableMatrix(
 					[c[0] + sp.I * c[1] for c in self.raw_value_complex2]
 				),
 			},
 			NS.Vec3: {
-				MT_Z: lambda: sp.Matrix([Z(i) for i in self.raw_value_int3]),
-				MT_Q: lambda: sp.Matrix([Q(q[0], q[1]) for q in self.raw_value_rat3]),
-				MT_R: lambda: sp.Matrix([R(r) for r in self.raw_value_float3]),
-				MT_C: lambda: sp.Matrix(
+				MT_Z: lambda: sp.ImmutableMatrix([Z(i) for i in self.raw_value_int3]),
+				MT_Q: lambda: sp.ImmutableMatrix(
+					[Q(q[0], q[1]) for q in self.raw_value_rat3]
+				),
+				MT_R: lambda: sp.ImmutableMatrix([R(r) for r in self.raw_value_float3]),
+				MT_C: lambda: sp.ImmutableMatrix(
 					[c[0] + sp.I * c[1] for c in self.raw_value_complex3]
 				),
 			},
@@ -1185,11 +1189,13 @@ class ExprSocketDef(base.SocketDef):
 		# FlowKind.Value
 		## -> We must take units into account when setting bl_socket.value
 		if self.physical_type is not spux.PhysicalType.NonPhysical:
-			self.active_unit = sp.sstr(self.default_unit)
+			bl_socket.active_unit = sp.sstr(self.default_unit)
 			bl_socket.value = self.default_value * self.default_unit
 		else:
 			bl_socket.value = self.default_value
 
+		bl_socket.prev_unit = bl_socket.active_unit
+
 		# FlowKind.LazyArrayRange
 		## -> We can directly pass None to unit.
 		bl_socket.lazy_array_range = ct.LazyArrayRangeFlow(

src/blender_maxwell/utils/bl_cache/cached_bl_property.py

@@ -75,6 +75,9 @@ class CachedBLProperty:
 
 		self.decode_type: type = inspect.signature(getter_method).return_annotation
 
+		# Write Suppressing
+		self.suppress_write: dict[str, bool] = {}
+
 		# Check Non-Empty Type Annotation
 		## For now, just presume that all types can be encoded/decoded.
 		if self.decode_type is inspect.Signature.empty:
@@ -122,6 +125,10 @@ class CachedBLProperty:
 			return Signal.CacheNotReady
 		return cached_value
 
+	def suppress_next_write(self, bl_instance) -> None:
+		self.suppress_write[bl_instance.instance_id] = True
+		## TODO: Make it a context manager to prevent the worst of surprises
+
 	def __set__(
 		self, bl_instance: bl_instance.BLInstance | None, value: typ.Any
 	) -> None:
@@ -144,7 +151,10 @@ class CachedBLProperty:
 				# Fill Caches
 				## -> persist: Fill Persist and Non-Persist Cache
 				## -> else: Fill Non-Persist Cache
-				if self.persist:
+				if self.persist and not self.suppress_write.get(
+					bl_instance.instance_id
+				):
+					self.suppress_next_write(bl_instance)
 					self.bl_prop.write(bl_instance, self.getter_method(bl_instance))
 
 				else:
@@ -162,7 +172,7 @@ class CachedBLProperty:
 				self.setter_method(bl_instance, value)
 
 			# Fill Non-Persistant (and maybe Persistent) Cache
-			if self.persist:
+			if self.persist and not self.suppress_write.get(bl_instance.instance_id):
 				self.bl_prop.write(bl_instance, self.getter_method(bl_instance))
 
 			else:

src/blender_maxwell/utils/bl_cache/managed_cache.py

@@ -20,7 +20,6 @@
 
 import typing as typ
 
-from blender_maxwell import contracts as ct
 from blender_maxwell.utils import bl_instance, logger
 
 from .signal import Signal
@@ -94,8 +93,9 @@ def read(
 	# Check if Instance ID is Available
 	if not bl_instance.instance_id:
 		log.debug(
-			"Can't Get CachedBLProperty: Instance ID not (yet) defined on bl_instance.BLInstance %s",
+			'%s (Non-Persist): Tried read() (key=%s), but Instance ID not (yet) defined',
 			str(bl_instance),
+			str(key),
 		)
 		return Signal.CacheNotReady
 

src/blender_maxwell/utils/bl_instance.py

@@ -74,7 +74,6 @@ class BLInstance:
 			The Instance ID is a `UUID4`, which is globally unique, negating the need for extraneous overlap-checks.
 		"""
 		self.instance_id = str(uuid.uuid4())
-		self.regenerate_dynamic_field_persistance()
 
 	@classmethod
 	def assert_attrs_valid(cls, mandatory_props: set[str]) -> None: