Harry Lime good comment on the capacity.

I do reuse my DD-X to extend the capacity, my 35mm tank holds 250ml so at 1+4 a bottle gets me 20 rolls without reuse. I've gone as far as 4 total rolls per 250ml batch, adding 10% extra time for each successive run. The OP would only need to re-use 1 extra run for each batch to do his 40 planned rolls. Just need a small juice bottle to store it over night or develop every other day.