I can't speak for PanF, but I use Delta 400 and have had no bad effects from leaving the film sit for a couple months prior to development. I use an X-tol-like homebrew, and I just give it my normal development.
With images I have doubts about (exposure too thin, etc.), I've used pyrocat and stand development with good results. This is with sheet film in which the first image was just not right, too thin to print. A couple of months is not a big deal, so normal development is most likely a good idea. Next time you have some film which is questionable, try some pyrocat at 1:1:150 and do a long, slow development. tim
Temperature is what you should care about if you leave films sitting for a while. When I'm not sure when I'll develop a B&W roll, I just throw it in the fridge until I have time to do it.
I just found a roll of exposed TMAX 100 buried in a pocket of a camera bag. I developed the film in my home brew metol/ascorbate developer and the negs look great. I shot the pics Easter 1999.