A few nights in a row of clear skies! (starting last night)
I did open and adjust the dec mesh. I started, per the instructions, by adjusting the hinge tightness It was very stiff - better than having play, but might as well get it to what it supposed to be correct. I did not notice until completing that adjustment that the motor bracket was physically blocking access to one of the 3 mesh-adjustment hex screws. So I had to loosen one hinge screw quite a lot and use the two sides together to move the bracket enough to get access to the screw, then readjust the tightness.
Remeshed a few times, rotating the worm by hand to see if I ran into a tight spot, then remesh again there. I probably could have kept that up longer and maybe found an even higher spot on the axis gear, but I think it's probably pretty good now.
I was anxious to prove to myself that I could put it all back together without any leftover parts and have it still work, so I did not notice until it was all back in that the hinge was back to being very stiff again. I really did not want to remove the motor and plastic shield again (I mean I could, but I thought up a lazier way to do it). I popped on Amazon and ordered a set of low-profile hex wrenches. That let me gain access to the locking screw with the plastic cover and motor still in place. The 4mm wrench was not *quite* stubby enough to engage the main screw itself, but the long ends have a ball that allow at least some engagement from an angle. I knew I didn't need to *turn* the screw, I just needed a tiny bit of nudge in the right direction. Success followed, so the hinge now moves easily but does not flop around on its own, and there is still no side-to-side play.
Spent a bunch of time last night running Guiding Assistant, varying how much I loosened the tension knob. About half way through I finally got smart and used a sharpie to mark the knob so I actually know how far I have rotated it. So I started again.
Basically, it is now 'OK' - far better than the >25000ms before remeshing.
(question for you El Corazon: when you say 'half turn' do you mean 180 degrees? Sounds like a silly question, but lots of people call 180 degrees 'one turn' when referring to the tensioner knobs, because it is way more practical to turn them 180 degrees at a time. Below, when I say 1 turn, I mean 360 degrees)
1.125 turn out from fully tightened: 3100ms
1.25 out: 3100ms
1.5 out: 2200ms
1.75 out: 1760ms
2 out: 1650ms
2.25 out: 1350ms
2.5 out: 1300ms
The knob itself was starting to feel quite loose by 2.5 turns out, so I stopped there and just let it guide while taking some pictures. Guiding settled in at 0.65" - 0.7" total RMS and always recovered after dithering. Then I learned what time M42 starts to pass behind a tree
I'll go back out tonight and concentrate more on just capturing and following guiding performance, hopefully with some time on both sides of the meridian.