Resolved: that having a loose general schedule is a pretty good idea, and that sometimes, throwing out any notion of a regular schedule is great.
Yeah, hyperfocus feels good sometimes. I think it may have had something to do with discovering the bag of golden monkey tea at lunch today and going "wow, this is really good!" and my system going "you have not had this much caffeine in ages!" and... actually, I feel great right now. I'm sleepy/tired but not crashing - this turned out to be the reset I needed after my post-FUDCon crash and subsequent week-of-not-a-lot-of-productivity (which was also a down-cycle I think I needed).
It's not that I'm inherently bad at stability - I don't actually need this hyperfocus cycle to be chaotic. If I figure out my natural rhythm for WHEEE! tinkertinker RAAAAAH! ponderponder WOOOO! shuffleshuffle and so forth, I'll be able to time it better - right now I can just barely sense it before I click into it sometimes, and I can consistently (if I remember to stop and think at any given point, or if I'm asked) tell what state I'm in.
That was a good run. I'm... going to bed now.