Shi**no pedals have float, but it's spring loaded, which means that if the cleat isn't perfectly aligned to suit your particular knee articulation through the pedal stroke, there's always a side load on the joint. Better than fixed cleats, but for those whose knees aren't machine straight there's the possibility of knee joint damage. I'm a big fan of Time A-TAC pedals, which have 'free float', which is, as it sounds, not spring loaded. In addition to rotational float they also have a few mm of side-to-side cleat movement. Years ago I had an accident (driven into by a drunk copper and went backwards head first through the windscreen) which left me with a right foot which turns out a few degrees further than my left, so the side to side float allows both ankles to match even tho my right foot is a bit 'Charlie Chaplin'.
What you need to get around your cleat indent problem is a set of these Crank Bros Shoe Shields:
www.ebay.co.uk/itm/357847136550