I punched through 4 holes in my BWS drifter kite surfboard for a single board travel combo. It's a little bigger than I'd prefer for my foil, but works fine. Bonus is the warm water jets tickling my feet while kite surfing.
Similar to Slappy's buddy, I picked up a tomo vanguard kite board with the intention of a 4 in 1 hybrid: kite surf, foil, surf, surf foil. I figure it's just about the smallest board that can float me and (just barely) be able to paddle it into a wave. I want to add some mast tracks, though I am waiting to see how the SUP foiling goes first, then hopefully borrowing a surf foil to see if I like it, before committing.
Agree with comments above though too: any time you create a hybrid board, you are chasing the best of both worlds, but possibly gaining the worst of both. EG "fun shape" surfboards that are too big to turn like a shortboard but also don't ride like a longboard. From the cup half empty perspective, my vanguard hybrid would be bigger than I'd like for a kite board, bigger than I'd like for a foil board, smaller than I'd like for a surfboard, and not the ideal shape for surf foil (want it short, wide, thick). But if I can't be bringing 4 boards with me, as a single travel board it buys me lots of options! The tradeoff is getting the minimum of what you need in order to pursue maximum fun opportunities. Get that moon on a stick, then take a big bite!