There have been general changes to CoreRedirects that may have helped UserDefinedStruct redirects work, but nothing intentionally meant to improve them. One Fortnite developer redirected a UserDefinedStruct to a c++ struct over the past year and it worked for them, so you should give it a try. There are likely some edge cases that will not work with the redirected struct, but maybe those are not relevant to your content. Even if it apparently works, to be robust you should manually view as large a sample size of possible of the blueprints using the struct and ensure that they look correctly hooked up, and resave the ones that look correct to remove their reliance on the CoreRedirect.
If you can give this a try and let me know of anything not working I would appreciate it; I’d like to start a JIRA listing the known issues.