tyFlow resets any time a dependent object is changed. Work could probably be done to make the resetting a little "smarter", so certain changes (like material) don't cause a reset on operators where the material has no effect. For now, the reset uses pretty broad strokes to cover all possibilities (some operators are dependent on object materials, for example).
From the editor right-click menu you can set the reset mode to "manual" to avoid an auto-reset when a change is detected. Then just refresh the simulation when you're ready to update it.
From the editor right-click menu you can set the reset mode to "manual" to avoid an auto-reset when a change is detected. Then just refresh the simulation when you're ready to update it.