I *really* like this idea because getting keycaps for Alps/Matias switches is such a PITA. Unfortunately, I'm really lazy and very time constrained. If this was an easy drop in solution that let me use MX keycaps, or better yet if I could just by pre-modded Matias switches with all the changes done, I'd be all over that.
That's a ton of work for you, but Matias has shown a willingness in the past to make variations for community use. (Their linear keys were specifically made to cater to the open steno project.)
If this goes well, do you think you could persuade them to make this a standard option?