@MattKing, thanks, I've been meaning to join this forum for a while now!

I guess my question is more about how to understand the relationship between developing times, exposure, and the rating that one gives a particular film. I'm getting nice results using the ISO 100 rating, but I'm still interested in understanding more about how I can experiment with rating it differently to see if I can get more out of the film.
The film I use for my 120 pinhole cameras are the Arista stuff I mentioned above, and Neopan Acros. Both have very "pinhole friendly" reciprocity curves. Especially the Acros. I can shoot exposures well over 30 seconds with no adjustment for r.f.

I recently switched all of my cameras' exposure charts over to LV instead of EV. That is, instead of changing my light meter to the ISO of the film or paper I am using, I meter everything at ISO 100 and compensate for the film speed after I get the light reading. Are LV and EI the same thing?

Thanks for the info,