RE: Controlled round Feed vs Push Feed
Last I knew, most CRF's today are all really CRF/PF's, perfectly capable of single feeding any way you try to feed them. Very few are really CRF's that require a gunsmith if you try dropping rounds in the chamber.
I don't really care either way, I've never had rounds flop out of my PF's, and I've never felt like I had any pains at the range with REAL CRF's (Like old mausers)