Speedrunner SethBling recently figured out the first sub 1 minute credits warp for Super Mario World and made a pretty detailed video explaining how it works. Seth uses 4 controllers and by doing that it puts certain values in RAM pushing the game into the right state to get the credits.

Seth provided a detailed Google Doc below that details how you can route this run yourself and all things you need to achieve it such as the Japanese version of SMW.

https://docs.google.com/document/d/1Cgr0jFw4AU8hF00JcQlOTRb8I1qPd-tF73LtTF4lzZE/edit
https://pastebin.com/V3EtvyGT