If you're okay just doing one sheet at a time, and already have a paterson 2(35mm)reel tank, you can put a 4x5 sheet in sideways, put the light trap in, fill with 800ml of liquids, job done. I reuse my rodinal working solution in one session this way with two tanks. 4 sheets of 4x5 = 1 roll of film so you can be quite economical with it. I dry out the tanks with some paper towel or jay cloth which means they dry totally quickly. I point the emulsion side inwards when loading it in the tank. I gave up on the "taco" rubber band method too after it was suggested to me. Having the one sheet in the tank loose allows for the solution to get everywhere it should.
I find developing sheets one by one is more helpful for learning anyway, as long as you're numbering/labeling your film holders and keeping notes as far as exposure, bellows factor etc. Plus, I picked up the trick of shooting the same scene twice (when possible) so you get a second chance if you find your first development time was slightly off or if you want to bump the contrast a little, you add more time to the second sheet. It does mean you end up with a double set of negs but that means you can play with those negatives too! It's all good
oh yeah and you can kind of fit two sheets in and they curve slightly like () that but i found i got slight "bruising" marks on the edges of my negs, not very far in and not a huge deal but since I contact print, I want to keep my negs rather clean looking even in the margins/borders.