Haha; that would be cool. Sadly no keyboard peripheral for the Jaguar, but they could probably do something similar with the keypad.
No this is Dr. Typo, one of the most prolific and and high quality creators of homebrew games for the Jaguar. This is his best of the best collection from the past 20 years and worth every penny. Looks like i can finally give away my burned CD's to a friend who just got a Jag CD, because it will be very nice to have these all on a cartridge.