I’ve used a 4mm thickness = height ring for quite a while. It was comfortable to put it on and off (I did this everyday, while cooking); the ring did touch the other fingers often, but eventually you learn to ignore it.
Since you’re saying that you have large knuckles, I imagine that it should be even easier for you in this aspect. Also note that thickness won’t matter much on putting it on/off, the main concern is the internal diameter = ring size.