To inject a little bit of data, the take rate for aftermarket magwells for Ruger PCC is about 0.3%. About one in 300 owners decides to use something other than Glock or Ruger magazines. Using injection molding technology, robust advertising, and selling to a channel would probably push to about 0.8% or so.
The most popular type is Beretta 92, the P320 is next, and P365 is the third most popular. P320 and P365 together sell more than B92. The CZ-75 type is often requested, but sells extremely poorly domestically. It's about one CZ-75 to 20 B92.
If you want to make money, Glock is the only type that matters. The rest is completely on the margins.