We are trying to upgrade D365FO from 1611 to 7.3PU12. We have started the code upgrade service and it created a branch under release with the appropriate version number.
Question: During code upgrade, where, when and how should ISV models be handled? Which of the following approaches is correct?
1. Add the new ISV models to the Main branch, let the code upgrade service run on them and then perform a VSTS synchronize in the 7.3PU12 onebox environment, resolve any code conflicts.
2. Let the code upgrade service run on the old ISV models in the Main branch, complete a VSTS synchronization in the new 7.3PU12 onebox environment, delete the old ISV models and import the updated (for 7.3pu12) ISV models.
Is either one of these approaches correct? If not, is there a better way to address this scenario.
Thanks