If you haven't been following Ocean Builders, now is a great time to check them out. They are in the final stages of completing the first unit of the first production SeaPod. It's a single spar floating home design being produced in Linton Bay, Panama.
You can watch the live launch here:
https://synapsefl.com/communityevent/ocean-builders-online-product-launch
You can order your own SeaPod for $295k here :
https://uncrate.com/ocean-builders-seapod
My take on the design - the benefit of the single spar design is stability in the waves, and the downside is that it's slower to move (higher drag). Think of it a bit like a car vs. an RV.
A full waterline yacht is a car - it's optimized for movement, has less interior space and comfort. A hydrofoil or any other small-waterline-area is like a sports car - higher cost, even higher speed. A spar is like an RV - it's optimized for space and comfort rather than speed. So it's slower to get to an anchorage, but once you anchor it moves very little in the waves. A boat gets there faster, but is only comfortable in sheltered waters. To a spar, moderate sized waves are about the same as sheltered waters.