i had this big explanation of slow speed/fast speed valving etc... hows the regular ride on the street? cracks, bumps at cruising speed? turn them FULL soft + 1 click. drive around. tight up evenly until all the wobble/pogo is gone after hitting bumps at say 30+MPH is gone. is that really 2/3 the adjustment?

if moving the slow speed rebound adjustment is making speed bumps more comfortable, i just resist judgement. I don't know anything about your setup but if your getting into the bump stops that would be jarring. if rebound adj is helping that on speedbumps, id wager it is also adding some compression resistance,(fairly common).

put some chalk/paint on your bump stop and then go over your speedbumps at your normal rate (slow right?) that will at least tell you where you are. and if you re hitting hard, more spring and/or more travel in this case might make it more comfortable.