If you look at the idea I outlined, you'll see it doesn't impact in any way on "normal" FT for the able bodied. They still have their 25 lanes of 2 targets including a proportion of standers and kneelers to whatever limits the rules permit.
When I get a call from a regular GP contender who tells me that his arthritis is such that after 15 lanes it becomes a test of endurance rather than an examination of his shooting ability then I think that time should be given to actually consider if the sport of FT could do more than it does to be inclusive. I might be in the same boat one day. So might we all.
Your opinion is that a sitting class is all that is needed. That may be true, but introducing one might be an occasion to see if as a whole we can do better. I believe it is wrong to exclude the disabled if by some small adjustment to rules or procedure they can be included.