My Oxford Sports tank bag has very strong magnets and the non slip bottom really helps limit bag movement. You have to compare because my Cargo Endurance brand tank bag, which holds much more, has weak magnets and not so grippy bottom. I constantly moves around.
Anyway, before you buy, take your time to compare.
I don't lean on my bag but I suppose you can with the RC, as the fairing support bars will keep the bag from interfering with the steering head.