Where I ride, SUPs aren't allowed at the main break, so they (we) congregate at one of the lesser breaks with the kayaks, beginners, etc. With all us pariahs together, I've noticed no differences in response between SUP, SUP foil, or surf foil.

It will be interesting to see what happens when I start surf foiling the Point ... SUPs may not be allowed, but I don't see any rule anywhere about prone foils.

But yes, on the beach and parking lot, the surfer crowd are slightly less stand-offish. Some are curious to know more.
Something I have noticed is the feedback from the beach is quite different between sup foil and surf foil. I am far from a ripper, but I get compliments on surf foil riding, versus on SUP it's more like "yeah, saw you out there". Frankly it's much the same as sup vs shortboard, on SUP you catch the wave and kinda mostly stand there, maybe some swooping turns, whereas on surfboard you tend to ride more dynamically. I have been SUPing for years and explain it as "a lot more fun doing it than it looks". I think sup foil is much the same, feels rad even if it doesn't look like much.