One obvious one is Cactus Canyon.
I think modifying WMS ROM is extremely difficult without the software that the developers used - and even were it possible, WMS has copyright in the images so modifying would probably be an issue. The workaround has been using PROC like the Cactus Canyon Continued code.
The old DE games apparently saved their data in a different way, which allowed the Star Wars code update and also the upcoming Jurassic Park update. While its questionable who holds the copyright for them, Stern as de-facto possible owner has signed off on SW, not sure how the third-party licences for those particular games was dealt with (although I think that the changes did not activate any issues as the existing data was used and re-ordered etc only).
