I just went with the wall approach. I hung a shelf to put the manual on, then put a board on French cleats above it and clip the plans to it. I rarely move the plans, but depending on what I’m working on, sometimes I’ll grab the board and hang it on cleats on another wall so it’s closer for reference. I always have binder clips on a few different sheets for easy reference so I don’t have to thumb back and forth trying to find a particular drawing. Low tech, but the setup works fine.