Would it be easy to create an option with bootstrapping data from a file to choose the option between real data and for example; "Dummy Data"? In case of the Dummy Data Outsystems will then import all of the data in the concerning the Entities/Attributes without leaving the Id's or Referenced Id's. Just a 1 on 1 import. Afterwards one could then change all of the concerning Data Types in Outsystems. Of course this data can filled with new data created from the application.
When the application is working as wished one should then remove the Dummy Data at once just by clicking a button, leaving all the Entities and Attributes empty.
I just experienced that importing Dummy Data by bootstrapping is a little bit time consuming. I also have some trouble to import the Referencing Id's within the Entities. It is of course possible, but not really efficient.
Regards