What about a "virtual PU impedance" parameter, assignable to a modifier? With a pedal, or input envelope we could "fake" the interaction...
Even if it worked you’d have to change that parameter while you also adjusted your guitar volume pot, so it would be kind of a PITA in my opinion.
It’s not like you can’t get some clean up as is too, just isn’t the same as certain fuzz pedals hooked up straight to the guitar, but only certain fuzz pedals do this even, really just germanium.
A lot of players don’t even like germanium, finding it too wooly and muddy, but others do like how it cleans up. A lot prefer a silicon fuzz which doesn’t clean up the same bit that can be a bit more cutting sound. Early era Hendrix vs Band of Gypsy era for example.
Other fuzz like a big muff works fine after a buffer with many preferring it that way, and I even run my hardware fuzz in the Axe loop, works and sounds fine.
Point is, it’s easy to blow this buffer and cleanup stuff out of proportion. Isn’t a factor in most cases, just for certain vintage fuzz deigns, ala a analogman man nkt275, bit if you like bc108 or similar, it’s not even a real issue.
Bottom line is guys are doing Hendrix, Gilmour and all those classic fuzz tones with the Axe and it sounds great, so sure one can complain about the cleanup, or that a certain big muff isn’t modeled which Gilmour used, but the results speak for themselves.
Has anyone felt Brit Floyd doesn’t sound “right” because their Axe’s didn’t have a certain model ? I don’t think so, they are always spot on tone wise. Heck, Bobby didn’t even use a muff models at all and sounded great.