What are your thoughts on Side Planers?

[dubob]

Do I need something to block the ring from sliding onto the trolling board arm?  Like a stopper?

I'm guessing it will not matter.  After ___ number of release clips pile up at the board, there might be some interference with how well the board tracks true.  If that happens, you would need to reel in the board and remove the clips.  My boards are large enough that it has never happened.  Just go for it and adjust if needed.