I've used my CP-31 for B&W
The way I do it is to run tank 1 as a water bath to soften the gelatin. I know that it is supposed to be the dev tank, but mine has the digital thermostat in a DOA state, and I have klugded an analog thermocouple to allow me to run it to within a degree or so of the desired set point.
I do this with RA-4 also - some of the older supra has a blue dye that comes off in this bath, so it doesn't give the developer more organic stuff to oxidize off and die faster.
Tank 2 I feed 1:2 agfa100/dektol/d72 generic cold tone developer. I never expect it to last past one session; With the roller transport and a big printing session you can almost exhaust the 2l of chems with the number of prints thst you can feed through it; I have no replenisher unit and I do ok. At the end of the night the developer is very dark, and gets tossed. If I ran B&W more, I would look to an RT designed developer, that would be more resistant to the aerial oxidation that the rollers give.
There is very little carry over between my tanks. If it has been a short session, I might tweak the pH of the fixer back down with a bit if acetic acid to counter for whatever alkaline influence the dveloper carry over levels impart. Most of the time the stuff is close to exhaustion, and I relegate it to a wait for some contact sheets in a tray use before it goes off to the HHW depot.
Tank 3 I feed with PE's home brewed superfix. Formulary TF-4 would likely work here as well. Hot, this potent fixer has the paper fixed in under the 45seconds it spends in the bath.
I disconnect the wash dry unit and wash the prints in a vertical rocker washer, then hang to dry, then lay on fibreglass screens. I don't trust the wash tank in giving a sufficient wash to get the hypo levels down, but then again I have never bothered to check; maybe I should becuase the way I do it now is certainly more work.
Other different ways to use a roller- accrue the dud B&W prints, and wash and dry them from any session you do - tray or roller, and then use then as el cheapo clean out sheets at the beginning of a session.
If you wash them between uses, you can also use RC paper as a 'carrier' to do B&W fibre paper in your roller. Wet the exposed fibre paper for a minute to soften it, paste it to a piece of larger otherwise scrap RC paper , and feed it into the machine. Don't feed them into the W/D module. At the end of a session, do a bulk fixer 2 pass with the accrued session's output, then wash ,and dry as you would a tray processed fibre print. It is still a lot faster than hand printing a big fibre job. The hot developer, and pre-wet emulsion gives you all the d-max that you are looking for in 45 seconds.
If you are getting fogged highlights, dial back the temperture of the developer tank.