I never hit my leg on the lower part of the frame so I dont think this would be a problem but you would have to make sure that you have a long enough break line to reach both positions, not sure what you would do with the slack when in 36er mode.
Definitely & Spinners would make his wheel go even faster.
Seriously, I would see no issues in welding both mounts on. I was going to suggest placing the mounts on opposite sides of the frame only to realize that that would make any possible snagging worse (DOH!!)
there must be thousands of people who own unis with brake mounts, but no brake. Can’t see it ever being a problem, I’ve heard of people putting bolts in the holes to stop crap getting in the thread but that’s about it. Really wouldn’t worry about it if I were you.