I hadn't thought about the hpf good thinking cheers
Many recording, live and studio guys value a cleaner bottom end to retain the bass and focus the drive on mid and higher frequencies to give a good balance of clean, clear low end and a bit of cut up top cut - aclean DI and a mic's cab for instance. The Grizzly might well sound massive in the lows if they're 'driven' but this isn't always desirable. It's true drive pedals do 'compress' and depending on the application it maybe better to have a cleaner low end but as ever depends on the application soound one is aiming for.
i'm confident you have enough of a concept and opinion on compression now to know what it does and doesn't do and how much a drive pedal is actually compressing versus an actual compressor. You've been through quite a few of both