Yes, this developer will die on you and suddenly at that. I had that happen even with the commercial version of it. Once you mix up a batch, you can use it one-shot or as a two bath developer. If you get the B bath into the A bath, the A bath dies. If you drain off A bath, then add B bath to tank, then B bath is still good. I have used B bath for up to 4 rolls of 120 film and it still does good. I usually use A bath for only up to 2 but sometimes 3 rolls of 120 before I throw it out.
I like this developer and have only had one roll fail to develop using it. I may have contaminated that chemistry but it may have been a temperature problem. I still can't decide. But since then, I have used it almost exclusively - almost everyone that sees my negatives think that I use Sepia to tone them with. They have never seen a staining developer at work before.
I have used this for maybe, 2 and 1/2 years and am very happy with it.