Updated from .500 to .550 with DJI Assistant 1.1-2 on Windows 10. Results:
My beautiful steady hover is back!
There's a thing where the barometer reports a foot or two off the actual height as registered by the bottom cameras, but I can vouch for the sensors' accuracy this time - I flew it Opti mode in a middling-to-darker-than-I'd-like basement as a test. (Since weather seems hostile outside.)
Mavic will drift a foot up, or less than a foot down, when the barometer and cameras disagree, but it'll settle in place after that.
Its side-to-side drift can now be expressed in inches- one, maybe two inches, to be exact. (I used a tape measure; .500 made me paranoid about stability.)
Had to re-enable multiple flight modes, precision landing, and low battery threshold (25% is my preference- often you just need a couple percent extra to come down and land before the worst beeping in the world assaults you mid-landing).
Startup noise is still inconsistent.
Litchi's extra modes don't seem to be fixed yet, but that's fine for me: Waypoint & FPV are 95% of my Litchi usage anyway- the UI is just quicker to use than DJI's, for me.
That's my report on as much as I could think of, for anyone who might want to ask any of it.
Update took about 15 minutes, maybe a bit more. Fan stayed on for all of it but the final restart.
One final thing: Auto-land still doesn't want to cancel. I flew it over a table, it decided I was landing it since I was too close, and I moved it quickly away from the table. It kept descending until it landed, and no amount of pushing up on the left stick would convince it otherwise.
Now that's everything. Promised.