Upgrade Questions with regard to Files element

[chrpai]

I'm using WiX v5's Files element to dynamically harvest a very large set of files. I am currently using default file versioning rules and MajorUpgrades with the default scheduling (afterInstallValidate).

Are there any gotchas / limitations / things to look out for if I wanted to switch to scheduling RemoveExistingProducts later in the install? Say afterInstallInitialize or afterInstallExecute.

Note: This MSI is a rewrite of a previous MSI so going from a legacy version to a modern version could have very different component ids and such. Going from modern to modern++ will be from the same wix source.