I don't have any experiences with re-using XTOL developper but I always use it with 1:3 dilution. Because of the dilution, I can't re-use de developper but I can process 16 films (135-36) with one liter of straight developper. I take 125 ml of straight developper and 375 ml of water to make 500 ml of dilute developper. I can process 2 films at the same time with this dilute developper.(posted 9141 days ago)I had very good results with dilute XTOL, it's now my favorite developper...
The processing times with dilute XTOL are on the Kodak website.