diff --git a/source/qdk_package/qdk/qre/models/qubits/_msft.py b/source/qdk_package/qdk/qre/models/qubits/_msft.py
index 1d74300e3e..0266f5484d 100644
--- a/source/qdk_package/qdk/qre/models/qubits/_msft.py
+++ b/source/qdk_package/qdk/qre/models/qubits/_msft.py
@@ -2,6 +2,7 @@
 # Licensed under the MIT License.
 
 from dataclasses import KW_ONLY, dataclass, field
+from typing import cast, Optional
 
 from ..._architecture import Architecture, ISAContext
 from ...instruction_ids import (
@@ -20,15 +21,22 @@
 class Majorana(Architecture):
     """
     This class models physical instructions that may be relevant for future
-    Majorana qubits. For these qubits, we assume that measurements
-    and the physical T gate each take 1 µs. Owing to topological protection in
-    the hardware, we assume single and two-qubit measurement error rates
-    (Clifford error rates) in $10^{-4}$, $10^{-5}$, and $10^{-6}$ as a range
-    between realistic and optimistic targets.  Non-Clifford operations in this
+    Majorana qubits. For these qubits, we assume that measurements and the
+    physical T gate each take 1 µs. Owing to topological protection in the
+    hardware, we assume single and two-qubit measurement error rates (Clifford
+    error rates) in $10^{-4}$, $10^{-5}$, and $10^{-6}$ as a range between
+    realistic and optimistic targets.  Non-Clifford operations in this
     architecture do not have topological protection, so we assume a 5%, 1.5%,
     and 1% error rate for non-Clifford physical T gates for the three cases,
     respectively.
 
+    Attributes:
+        error_rate: The error rate for physical Clifford operations (state
+            preparation and measurement).  Defaults to 1e-5, with a domain of
+            [1e-4, 1e-5, 1e-6] for use in design space exploration.
+        time: The time (in ns) for physical Clifford operations and the T gate.
+            Defaults to 1000 ns (1 µs).
+
     References:
 
     - Torsten Karzig, Christina Knapp, Roman M. Lutchyn, Parsa Bonderson,
@@ -46,25 +54,37 @@ class Majorana(Architecture):
 
     _: KW_ONLY
     error_rate: float = field(default=1e-5, metadata={"domain": [1e-4, 1e-5, 1e-6]})
+    time: int = 1_000
+    t_error_rate: Optional[float] = None
 
-    def provided_isa(self, ctx: ISAContext) -> ISA:
-        if abs(self.error_rate - 1e-4) <= 1e-8:
-            t_error_rate = 0.05
-        elif abs(self.error_rate - 1e-5) <= 1e-8:
-            t_error_rate = 0.015
-        elif abs(self.error_rate - 1e-6) <= 1e-8:
-            t_error_rate = 0.01
+    def __post_init__(self) -> None:
+        if self.t_error_rate is None:
+            if abs(self.error_rate - 1e-4) <= 1e-8:
+                self.t_error_rate = 0.05
+            elif abs(self.error_rate - 1e-5) <= 1e-8:
+                self.t_error_rate = 0.015
+            elif abs(self.error_rate - 1e-6) <= 1e-8:
+                self.t_error_rate = 0.01
+            else:
+                raise ValueError(
+                    "Invalid error_rate value. Must be one of [1e-4, 1e-5, 1e-6]."
+                )
 
+    def provided_isa(self, ctx: ISAContext) -> ISA:
         return ctx.make_isa(
-            ctx.add_instruction(PREP_X, time=1000, error_rate=self.error_rate),
-            ctx.add_instruction(PREP_Z, time=1000, error_rate=self.error_rate),
+            ctx.add_instruction(PREP_X, time=self.time, error_rate=self.error_rate),
+            ctx.add_instruction(PREP_Z, time=self.time, error_rate=self.error_rate),
+            ctx.add_instruction(
+                MEAS_XX, arity=2, time=self.time, error_rate=self.error_rate
+            ),
             ctx.add_instruction(
-                MEAS_XX, arity=2, time=1000, error_rate=self.error_rate
+                MEAS_ZZ, arity=2, time=self.time, error_rate=self.error_rate
             ),
+            ctx.add_instruction(MEAS_X, time=self.time, error_rate=self.error_rate),
+            ctx.add_instruction(MEAS_Z, time=self.time, error_rate=self.error_rate),
+            # NOTE From __post_init__, t_error_rate is guaranteed to be non-None
+            # if error_rate is valid, so we can safely cast it to float here.
             ctx.add_instruction(
-                MEAS_ZZ, arity=2, time=1000, error_rate=self.error_rate
+                T, time=self.time, error_rate=cast(float, self.t_error_rate)
             ),
-            ctx.add_instruction(MEAS_X, time=1000, error_rate=self.error_rate),
-            ctx.add_instruction(MEAS_Z, time=1000, error_rate=self.error_rate),
-            ctx.add_instruction(T, time=1000, error_rate=t_error_rate),
         )
diff --git a/source/qdk_package/qdk/qre/models/qubits/_neutral_atoms.py b/source/qdk_package/qdk/qre/models/qubits/_neutral_atoms.py
index db60ce216e..706694ae98 100644
--- a/source/qdk_package/qdk/qre/models/qubits/_neutral_atoms.py
+++ b/source/qdk_package/qdk/qre/models/qubits/_neutral_atoms.py
@@ -121,7 +121,11 @@ def provided_isa(self, ctx: ISAContext) -> ISA:
                 T,
                 encoding=Encoding.PHYSICAL,
                 arity=1,
-                time=0,
+                # NOTE: We assume a time of 0, however, some transforms may use
+                # the time in arithmetic expressions, which require its value to
+                # be non-zero.  Setting it to 1 leads to no or at most
+                # negligible contributions to the overall resource estimates.
+                time=1,
                 error_rate=0.00001,
             ),
             ctx.add_instruction(
diff --git a/source/qdk_package/qdk/qre/property_keys.pyi b/source/qdk_package/qdk/qre/property_keys.pyi
index ae1f8f32ea..e9df7d84a4 100644
--- a/source/qdk_package/qdk/qre/property_keys.pyi
+++ b/source/qdk_package/qdk/qre/property_keys.pyi
@@ -5,8 +5,6 @@ DISTANCE: int
 SURFACE_CODE_ONE_QUBIT_TIME_FACTOR: int
 SURFACE_CODE_TWO_QUBIT_TIME_FACTOR: int
 ACCELERATION: int
-ATOM_SPACING: int
-VELOCITY: int
 NUM_TS_PER_ROTATION: int
 EXPECTED_SHOTS: int
 RUNTIME_SINGLE_SHOT: int
@@ -23,6 +21,9 @@ NAME: int
 LOSS: int
 LOGICAL_CYCLE_TIME: int
 CODE_CYCLE_TIME: int
+ATOM_SPACING: int
+VELOCITY: int
 ASSUMPTIONS: int
 FEASIBILITY: int
 TARGET_YEAR: int
+BLOCK_SIZE: int
diff --git a/source/qdk_package/src/qre.rs b/source/qdk_package/src/qre.rs
index 64b4ad743e..170c539de0 100644
--- a/source/qdk_package/src/qre.rs
+++ b/source/qdk_package/src/qre.rs
@@ -1623,8 +1623,6 @@ fn add_property_keys(m: &Bound<'_, PyModule>) -> PyResult<()> {
         SURFACE_CODE_ONE_QUBIT_TIME_FACTOR,
         SURFACE_CODE_TWO_QUBIT_TIME_FACTOR,
         ACCELERATION,
-        ATOM_SPACING,
-        VELOCITY,
         NUM_TS_PER_ROTATION,
         EXPECTED_SHOTS,
         RUNTIME_SINGLE_SHOT,
@@ -1641,9 +1639,12 @@ fn add_property_keys(m: &Bound<'_, PyModule>) -> PyResult<()> {
         LOSS,
         LOGICAL_CYCLE_TIME,
         CODE_CYCLE_TIME,
+        ATOM_SPACING,
+        VELOCITY,
         ASSUMPTIONS,
         FEASIBILITY,
         TARGET_YEAR,
+        BLOCK_SIZE,
     );
 
     m.add_submodule(&property_keys)?;
diff --git a/source/qre/src/isa/property_keys.rs b/source/qre/src/isa/property_keys.rs
index 98b5bde15a..5c9fb56e95 100644
--- a/source/qre/src/isa/property_keys.rs
+++ b/source/qre/src/isa/property_keys.rs
@@ -50,8 +50,6 @@ define_properties! {
     SURFACE_CODE_ONE_QUBIT_TIME_FACTOR,
     SURFACE_CODE_TWO_QUBIT_TIME_FACTOR,
     ACCELERATION,
-    ATOM_SPACING,
-    VELOCITY,
     NUM_TS_PER_ROTATION,
     RUNTIME_SINGLE_SHOT,
     EXPECTED_SHOTS,
@@ -68,7 +66,10 @@ define_properties! {
     LOSS,
     LOGICAL_CYCLE_TIME,
     CODE_CYCLE_TIME,
+    ATOM_SPACING,
+    VELOCITY,
     ASSUMPTIONS,
     FEASIBILITY,
     TARGET_YEAR,
+    BLOCK_SIZE,
 }