Decided to try my hand at paladin healing in an LFR raid (I haven't really played healer since the original TBC ...). I'd say it went well but at the same time, I don't think I actually did that much? I know LFR isn't very hard, especially not on the tank and spank bosses, but surely everyone's just overtuned and outscales the content for it to be this relaxed.
I find LFR to be useless to gauge my healing. Trying some Mythic 0 runs and that will definitely show you if you've got the class down or not. Or at least a lot better than LFR.