I'm not being pessimistic or anything, but..... given that there were issues with SDM, and Pentax never gave a user option to disable SDM for screwdrive on AF in the menu, I think that DA /FA will most likely be an auto function unfortunately. If it is a Da lens on the camera, it will crop automatically, if people want more, they will have to buy more lenses that are coming on the lens roadmap. That's marketing and creating a market for sales and growth 101.
of course, you could maybe just blank off a couple of connections on the lens with a bit of tape so the camera doesn't know what lens is on there, and run in manual mode, ( there is always a way around a problem... )