[Saphire]

Ron hopefully someone can come back to you with more information.

When I started out doing the odd film I only ever did the one-shot method I remember working out the dilutions and times so I could just use the one small tank, then disposing of the chemical and use fresh for the next set of films, I found I got more consistent results that way.
I am not sure whether I did use the ID11 further diluted or the perceptol, it maybe better if someone else could come in and say whether the ID11 can be further diluted and times altered accordingly. I don't want to give you the wrong advise.
When I did deep tanks to develop 50+ films at a time I had to alter the times after doing so many. To test how much I had to alter the time, I had a roll of film taken of a test card, I kept this roll and just cut off a small piece containing a couple of frames and gave it the adjusted time in the chemical to check it out. The same for the one shot solution it makes sure you don't make a mistake on your important negs.