When I built and posted my first few bows back in '99 - early 2000, I had made locator grips with palm swells and cut in shelf. I took a Lot of heat for doing that from the die hard traditional / primitive bowyers. I usually had a fairly beefy handle section and only cut deep enough to support the diameter of the arrow.
I see a lot of bows now with the same grip I made long ago, and a cut in shelf in over 70 bows hasn't caused a failure as yet.
The beauty of making a bow is freedom of choice in design - length, width, draw weight, finish, string type, recurve, flatbow, ELB, and on and on...........
If you want to cut in a shelf - why not? If it doesn't work for you, there are plenty of other options. It's Your Bow.