Where a normal race foil kite can not match, because it drops easier and folds if wind is gusty, so a lot more tricky.
In steady winds, the UL foil kites are awesome, but the UL strutless LEI can really hang without the same issues nor risk, in marginal winds.
Yes and no. BRM Cloud is exceptional yes. Lightweight, reactive and fun to fly. Both can foil in winds where relaunch won't happen even in flat water and shallow water. Ozone Hyperlink in regular cloth stays in the air better with static flight and has more power size for size. Ultralight cloth or possibly Concept Air would add to that ability to stay in the air by an even bigger margin. Mid aspect easy to fly and lightweight foil is more likely to stay dry at the low end. Also less likely to luff and crash on the seawall while entering and exiting the water.
I haven't flown the ultralight one strut leis Peter described, hell I've never even seen one. Standard foil kite will out float standard lei at the low end.
BUT! Ultralight wind swell/whitewash combo is a nightmare for getting going on a foil. Particularly onshore winds you need freaking good kite and foil skills to get going and probably a short mast so you can get going shallower. Some times it's just plain impossible to get out past the breakers even if you have ample wind.
Look for cross on wind, that is much easier as you can use the kite to power you through the white wash and out to a save water start position.
I often spend time in southern California in the winter, light onshore wind and big surf is the norm. I find that if the surf is more than 1 meter and the wind is less than 9 knots, it is really tough no matter what the kite. I usually go to a beach where it is shallow for a ways, that seems to help with the surf a little. But getting out to chest deep water without getting thumped by a wave is tough, getting up on the foil quickly is a challenge. I find it tough with a foil or a LEI.
You need to try the Conceptair Pulsion. So stable in light breeze that it does not move from the zenith even "yoyo-ed" by waves and has instant power peak for rapid waterstart . With 60kg and the 12m , sweet spot is 8 knots where is works without any skills, so 7-9 knots is really easier than any other kite up to 70kg. You can foil-up very fast. I have no financial interests nor kite price arrangement with CA.