OK, so here is what I have found as the best way to make 8100 adjustments on the vehicle:

1/ Hex goes
2/ into an adaptor that goes
3/ into a 1/4 inch STUBBY flexible head ratchet

Lift vehicle by rock slider or flex it in order to expose the rebound bypass tube--the rest is easy though each movement is probably 1/8 turn. I roughly figure 8 per one full turn. One can also learn to measure the exposed thread as an alternative.

So what about on-trail adjustments?

I have a small secondary garage jack that won't be hard to carry but need to figure out an extender. The Harbor Freight aluminum racing jack 1.5t (mine is bigger and heavier) would be perfect for serious outings. I have carried my heavy one when not with the kids/dog. In any case, having a reliable quick jack is a good idea.

EDIT:

So the tool above takes about 6 movements per 1 rotation on compression. So, 6 for 10% stiffer from fully open, roughly 60-70 for full closed.

The rebound, lol, involves smaller movements so they are countless, possibly double those needed for compression. So here I just measured the difference in length of the treads to see how to get it to half way, maybe a little softer than half way.

Clearly making finite adjustments with this will be...yeah, very finite with like 120 movements on rebound (hence you need a ratchet not to go insane).