FWIW, I bought Glycin from PF and used some to make Ansco 130. I then put the remaining glycin, still in the original PF plastic container, inside a freezer bag and put it in my freezer. Over the next two years I used some for more 130 and returned the bottle to the freezer. After about two years I decided to test to see if the glycin was still good. I mixed up a developer with glycin as the only developing agent and tried it on film. It worked just fine. Based on this limited test, I would say that glycin will last a good while in the freezer.
I think it was Tom Hoskinson who make the glycin solution. I don't remember what he used, but I have been able to get it to dissolve in TEA, although there are reports that it won't. Worked for me, though.
juan