But how low is too low on RPMs?

Yeah, my buddy had a similar thing happen with a rehab mustang. He put on a wedge pad and the horse was off for like three days, just short-striding and grumpy. They backed it off to a 1-degree pad and gave him some bute, and then he came right around. Maybe the change was just too much for him all at once.

The fruit fly battle is real. It gets easier once you nail the browns to greens ratio.

Actually saw a video where someone used a piece of cardboard from a cereal box as a temporary spacer. They just cut little strips to the right thickness and slid them in. It worked for small jobs where the plastic ones were too thick. Sometimes the simplest fix is just using what you already have lying around the house. That paint stick idea sounds pretty smart for keeping things level though.

How many hours did you put in before the Bosch felt like a real upgrade? I'm trying to decide if my current struggle is just part of the process or if better tools would actually save me time.