Entering functional currency simplified vs. standard currency

Summary

Need to restrict users to entering correct functional currency based on Entity

Content

Hi - looking for some feedback on this

Requirement is for user to enter data into forms in functional currency by Entity.

With Standard currency option this works as expected.

With simplified currency it appears user can select any currency they want, which means they have to know the currency for the entity and could result in errors. Is there a way to enforce the user enters to the correct currency based on Entity they select?

Options considered

1. Use valid intersections to try to enforce the correct entity/currency combination is selected.