Serviced the rear hub--cleaned out old grease from the freehub mechanism, clean/reassemble, lube. Axle bearings okay, so I left them for the next round, but shot a bit of grease in the left side, since it looked a bit thin.
I wound up replacing the AER bearing that I put in the top of the headset on the mountain bike. It turns out that the creaking I had been chasing was unrelated, BUT, I felt like on a FS bike, the top bearing was likely to be stressed more than on a rigid bike. Nothing scientific, mind, but I pulled it out (noted it was fine, incidentally), and set it aside for a different build. I scootched the preload collar on the coilover a bit more, and the knocking sound went away. I think I have a 600 on there now, and the ride height is right with the spring just barely preloaded.
Cleaned up both brake calipers, addressed the fluid issue in rear brake (never de-gassed mineral oil before bleeding before, but I'm going to now), and wound up replacing the front pads with a pair of non-finned pads, since they were down to ~.75mm of pad material...and the reservoir was having problems compensating for wear.
Luckily I have 2 pairs of non-finned pads for the winter, and another pair of resin pads (but don't really want to use those unless I have to). I expect to have to wait a few months to get my brake pads