I played with this some years ago but with a different outlook. I used to carry a small bottle of HC-110 concentrate and a small bottle of fixer concentrate when I went on a trip. I used each as 1-shot, but instead of dumping the developer, I added a small amount of fixer concentrate to the tank at the end of development time. Immediate and thorough agitation assured even development. I don't remember all the details, but I do remember getting good negs. It might be worth a try.