When recording data offline (using Mobile for Laptop) the Framework should already check (before saving or event-triggered on leave of the field) if the data entered by the user is valid for the respective field-type.
Salesforce field-types should be synchronized to offline as well, so MFL knows for example how many digits a numeric field has and prohibits storing of values out of range.
What is the underlying problem do you intend to solve with this idea?
Wrong data-types lead to synchronization errors when user tries to synchronize. It can mean a lot of additional work to resolve all the issues afterwards instead of being stopped by the system at the time of input.
How is the problem being addressed today, if at all?
One has to create validation rules for every single field in each SFM (!) - and update them in case of a change of a field - in order to avoid those synchronization errors.