If you try, be careful, as you'll be drilling into the slide in an area where you might interfere with the firing pin assembly.
Anything you do would arguably interfere with the gun working with a holster.
I sure wouldn't do it -- but its your gun, not mine.
The Kadet is kind of difficult to charge using the slingshot method. If I had a slide racker it would be a lot easier. I plan on using this set up mostly for local steel matches.
How would you use a .22 in steel matches, or getting ready for steel matches? Except for the first shot from the holster, I don't see where it would be of much use, with the Kadet Kit mounted.
(Maybe there's more to steel matches than I appreciate?)