FWIW, i'm using the Wheeler folding anti-cant devices on my rifles, mounted on the left side for my lefty shooting (can't see with my right eye - so I can't mount it opposite side from dominant eye/trigger hand).
no complaints or problems so far - but my shooting is generally limited to 400 yds or less.
device does stick out from the scope when opened. I can't speak to whether it sticks out too far for someone using it on the opposite side of the scope from their trigger hand.
when folded, the device does not stick out any further than my turrets, so I haven't had any issues with the device getting hung up on brush, saddle scabbards or Eberlestock pack scabbard.
device's mount is narrow enough that it has fit in between rear rings and turrets.