Ah, ok. I messed with it for a loooong time this weekend, and I guess I have it dialed in.
I was definitely looking for something different than the Keeley, so that's not an issue. I'm still not convinced that I can actually hear it beyond my
wanting to hear it (I've been doing audio stuff for like 20 years, and at this point I feel like I know what compression sounds like) but after playing with it for a while, I can "feel" it in the way the amp responds, etc. It's pretty cool in that regard. Not what I was expecting, but maybe what I actually needed.
The bias is set way higher than spec, but not all the way up to 5V, where it was in the middle of the range. I don't remember where it wound up, but probably around 2.5-3V. In the old days of the MIMF, I remember an argument that arose when guitar tuning machines with high gear ratios started to become popular. The primary advocate for using the old, lower ratios made the argument "I just don't want to have to turn the knob hundreds of times when I change strings, and don't care if it's a little more finicky when actually arriving at the pitch. We're musicians: we're used to making extremely small adjustments." That has always stuck with me for some reason, and I tend to agree in principal. But I don't think I've ever made such extremely small adjustments to anything as I did with that trim pot.
I have a set of precision screwdrivers, so I was able to find one that pretty exactly matched the slot of the trimmer, but found myself not so much "turning" the trimmer as delicately bouncing the blade of the screwdriver within the microscopic amount of play so that its inertia would nudge it to where I needed it to go.
As always, I appreciate the guidance and patience. This is resolved.