I've read that you can push/pull in stand development and the times still don't really matter, meaning you can develop say a roll or sheet of a 100 ISO film along with a 400 ISO film in the same canister.

But that seems very counter-intuitive because that means you could get similar results with a wide variety of exposures?

I tried stand development with HC-110 and HP5+ yesterday (4x5) and I did get some pretty nice results. The negatives looked kinda like a comic book given the highlights were pretty deep but the rest of the negative looked a bit thin. They scanned pretty well though and still showed some nice HP5-like contrast. Haven't tried a darkroom print yet (I can only do contact prints at the moment).

The approach I really like since I can be lazy and/or go do other things while it's developing But the lack of having to care about ISO or exposure has me a little confused there (and somewhat concerned).