I only offer these comments because it is the lowest liter board that I have ever been able to paddle.... (more on that in 4th paragraph)
and I was very surprised that I actually found it quite comfortable.
I do have a 9'0 Flash custom, with
very little rocker or nose kick,... I call it the "flatish"..... nothing like the rocker Flash, but same outline, volume
never ridden a standard Flash, so I can't comment on Flash surfability, but I wanted to relate stability and "board feel" to you.
Oddly enough... the standard Flash is the only Sunova that I have never had a chance to surf.
It has very nice stability for this shape. I took it to Portugal, as my 2nd board.
I weighed about 100 kg during my time over there.
At 133 liters, it fell right at about 1.3 ratio of body weight to volume which is right at "advance rider" volume ratio
and yet, it was very reasonable, even on choppy days. (4th pic)
I use it easily at my current weight of 106 kg - 1.25 w/v
When I was at 107 kg, I stepped up on a friends 8'6 Flash, in perfectly flat harbor water.
107 kg on 112 liters and yet, very easy to paddle, spin and mess around on.... paddled a short distance, many tail spins, and switching feet etc.
I had zero stability issue on it, until I stopped paddling... and it sank

There is no way I ever could have surfed that size, because I simply could never get to a standing position, in the ocean
Hopefully this info has some value, when you are choosing a size.

sinking

Screen shot from "Choppy days are SUP fun" - shot in Portugal