What Doremus said - and
use one shot developer- too much exposure to oxygen during constant agitation to keep the developer for later, even if you do consecutive runs. Yeah, constant agitation, like he said, establish a pattern.
A good start would be to expose 2 sheets identically, back to back. Do one with your tank, one with tray method, one shot developer for both, you'll know how much to allow for tray. Rule of thumb for me is 20% less for tray constant agitation vs tank with agitation every minute or 30 seconds. You'll be close.