I’m a green P3, and not an expert on USHPA regs or how they rate sites, but I’ll take a stab at this. Hopefully, someone more knowledgeable will jump in here.
Marshall and Crestline are both, by definition, P3 launches, since you can’t see the LZ, so it seems like any attempt to classify those for unrestricted P2 use would be out.
Seems like one could make an argument for the 750 (to remove the sign off requirement, it seems like it would have to be re-rated as a P2 launch). However, the scenario I’m thinking of would be a visiting P2 showing up, seeing that the 750 is a P2 launch (so they might assume that the launch, approach, and LZ are simple and good for beginners), and launching at noon to get some flights in. We all know that the entire area around the 750, the approach, and the LZ are pretty thermic midday, but the visiting pilot probably wouldn’t. We’re already seeing that visitors are just showing up and flying without reading the site briefings or asking for a site intro from the locals. Maybe the only thing that they know about the site before they fly is what it’s rated.
The site sign-off issue, I know, is a hot topic at the moment (between instructors, students, and even USHPA/RRG), but to me, I think it’s a great way for pilots who have been learning and flying at our site for some time to be able to get more flights and experience under their belts. I think more advanced pilots or instructors would have more to say about how they feel about P2s having free run of a launch and the LZ.
As for the standing issue of pilots violating the CSS rules – just about every case I’ve seen so far have been pilots that know the rules (and knowingly break them) going up to Crestline and launching. As said before, Crestline is, by definition, a P3 launch. They could have very easily chosen Marshall or the 750 to get more flights in (as some of the violators already had a site sign off) but they chose not to. Clear that in these cases, giving them more options wouldn’t have made any difference.
Just my 2 cents.