Be sure to have a spare piston. Drilling holes is a fun way to learn things, but it's hard to go back.
For one experiment, I put a small bleed for the rebound. When riding, I noticed I had to run the rebound adjuster at about 11 out, while normally I would run it 14 out. It took awhile to figure it out, but eventually I learned it did the following:
At 11 out, the rear would rebound correctly for about the first 1/2 of wheel return and felt fine. But when launching of larger / abrupt faces of jumps, the bike would shoot strait up in the air. (almost looped out) It turned out the hs rebound was to slow and didn't pop the back of the bike up enough to level me off. At the normal 14 out, hs rebound was ok again, but the rear was busy and boingy over smaller stuff.