What is your purpose of pushing or pulling? Contrast manipulation, or simply want the best image quality you can get?(posted 8192 days ago)HP5+, TMX and probably many other recent films tolerate overexposure and overprocessing much better than older films, including currently sold Plus-X. This is particularly so with HP5+ in XTOL or my D-76Ad, and TMX in Microphen or HC-110. I usually simply have to expose longer during printing without too much contrast adjustment, and I don't get noticeable increase in grain in highlight area. (PX needs contrast adjustment and I see much bigger grain in the sky, reflections, etc.)
I simply recommend to expose and process normally, and make necessary adjustments during printing process. It's a matter of finding the right combination of film, developer, and paper for the kind of images you are looking for.
I'm not against zone system, but I never felt like I need it except for a few exceedingly rare extreme cases.