"As long as you use the proper amount of chemistry per volume of film, you will continue to get properly developed negatives."(posted 8342 days ago)That is until you experience "The dreaded Xtol failure". Happens suddenly... the developer just doesn't work. No rhyme or reason and certainly not because you used too little stock in the dilution. I used 200ml stock per 8x10 film unit & still got hit with it.
The Yellow Peril recommending against 1:3 has more to do with Xtol's reaction to chlorine, iron, calcium and hard water than more folks using less than the recommended 100ml per 8x10 film unit.