Thanks so much for this. These buttons feel so good mechanically, I would have never guessed they were broken. Glad I found this thread. I don't normally use the L an R buttons even if they work. Bought this system for $5 and wouldn't have used it without this config file.
Regarding the people who say that this is not needed because nobody would use a system without L and R, there are people that normally don't use them and there are tons of games that do not use them.
Now that I know this works I will order new ribbon cables but without this config file, this system would never get used again.
Regarding the argument that this is an edge case not worth 'fixing', I agree it's an edge case but there are more uses than just broken buttons. Those buttons can be hard to reach for some people such as those with injuries or ailments.
But, more importantly, this wouldn't even require a code change. It would be super simple to package an extra config file or two with this. I assume there is testing of the functionality anyway, just copy the file during a test and include it with a note to select the one that suites your needs.