I was inspired by Tony Logosz (Mr. Slingshot, bottom pix) to see how small I can go.
Chopped as much off my Isonic 121 as I could - now about 75L and 1.5m (4.9ft).
Amazing on-foil feeling, carving is even easier without the swing weight. Cool looking down and seeing water instead of board

Slogs pretty well, the wide fat nose helps - as long the board is moving slowly forward the foil generates enough lift so it doesn't sink and is surprisingly stable.
It's heavy though, it would be awesome at half the weight - looking forward to getting a mini Slingshot Wizard

A fun option for strong steady sea breezes on the ocean - bring on summer.
Who else has a small one?

Tony Logosz