Ok never mind I’ve solved this as I found an error that I didn’t notice this the first time around.
[2025.06.02-21.50.02:247][ 0]LogCoreRedirects: Error: ValidateRedirect(Type 2) failed to find destination Class for redirect from RvnScreenshotUtilityActor to /Script/RvtImageGenUtility.RvtImageGenActor with loaded package!Despite all the redirects successfully replacing the old RvnScreenshotUtilityActor with the new class, I missed that there was a lone error that this class couldn’t be found. Ended up that it was just a typo! The RvtImageGenActor was actually RvtImageGenActorUtility.
Fixing that and it all works.
So I hope this helps someone reading that this is the sort of error you need to look out for if things don’t work immediately.