I have a sorry tale to report. While XTOL 1+1 works great in a Jobo, 1+2 is a bad, bad idea. I ended up with dramatically thin negs from TMX (in 120, on 2xxx spirals) and most problematically, the edges are denser than the middle. I think what's happening is that the spirals are agitating the developer a bit, but in the middle of the roll there is not enough slosh going on.
I suspect also that the liquid in the centre of the spirals never reached the outer part where the film was and vice-versa, so the tiny bit of developer between the film in the spiral just got exhausted. I went first with official times, found it very thin and extended times by 25% which made very little difference, hence my conclusion of poor mixing and local exhaustion. With 3 rolls in the 2553 tank, that's 900mL of developer instead of 600mL at 1+1, so there's a lot more developer hiding in the middle where it probably never goes near the film.
Worse still, these are all my Great Wall shots. I would normally shoot Acros but ran out and bought TMX at Wukesong. I don't normally shoot TMX... The photos are fine for scanning but look like they'll be a bitch to wet print.
Or it could be the "bad batch" of TMX reported elsewhere that people are saying produces underdeveloped-looking results compared to what TMX would normally do. Since TMX isn't my normal playground, I couldn't say. The XTOL itself is fine as I developed some other films on the same day from the same bottle of stock with no issues.