when I had the 8x10 besellers I only used what the trough could hold..I think it was maybe 4 oz?????....at that time I was using the 2 part developer diafine though so there was no dev adjustment needed.
I've found that with a roller base the dev times need no adjustment compared to roll film agitated every 30 seconds in 16/32 oz tanks with 120 reels. but then again, maybe I agitate a bit more vigorously than most....than you do....I'd just start with what you've been using and see if it's ok...if not...adjust to taste.
as a side note i tried putting a tank of 120 reels in a processing drum sideways in the roller base to develop them on reels using the "roller method"...it worked great BUT, it seemed that I actually got LESS development action than hand agitation using the same dev time!!!!! no kidding.....I"m going to run another test...maybe my exposure was off???? I don't know...far too little data to determine yet.
I used to put screens in them drums too--to keep the film from sticking to the walls---I've had imprints in ilford 8x10 film when I did this---the screens imprinted themselves....somehow if the dye comes out during the dev step but doesn't come out fully, then when it comes out in the fix step, it doesn't come out the same---
you'll probably get unevenness due to this--I still have problems with it despite all my best efforts...of course I'm very critical these days--most people don't seem to notice---if you're making prints, you probably won't notice at all since the imprints don't seem to show up in the prints noticeably.