Inside a MBD world, it's important to use the correct tolerance system and model DTL settings. A mix out of different settings is creating downstream problems and mistakes. Therfor a user needs to use ISO DTL settings and ISO tolerance settings inside a model. Changing a model tolerance setting from ISO to ASME or wise versa at a later state will change all finished defined annotation tolerance values inside a MBD model. This is very critical during an active design phase and also for downstream processes in a digital world. The model with its tolerance value and setting is driving the quality of a downstream process. In case a tolerance system change will be done at the end of a design process, because the validation process is reporting a wrong selected tolerance system compared to DTL settings, all tolerances will get converted automatically and needs to get reset manually. This is a very big and potential error for downstream usage and model quality.
If the tolerance system of a model get changed, CREO should ask if all tolerance values should get converted to the new selected tolerance system or if they should stay as defined and not get modified. A tolerance system is equal to a unit system, here CREO is asking the user how to handle the conversion.