I can not comment on the question about that low wind...
Here we dont bother using surfboards or waveboards untill you can ride with smaller kites than 9 m2, as even with a 9 m2 waveriding does not work well, too big.
When wind is lower, you can hydrofoil, with the same smaller kites, so a win win instead of a boring big kite on a board where you can do nothing, not even go upwind well.
IF you had asked about a good strapless kite in general, it would be a kite with loads of range and depower, not much grunt.
Not too C shaped, as not sufficient range and depower.
Personal whether you want it to fly forward to the edge or not, some do (I do), others dont.
The main point is, you want a kite you can "kill" completely, so you dont get pulled of the board, or the line on the wave, going DTL (Down The Line).
Regarding big kites, I have never seen anyone using these with a surfboard, so can not comment on your question, sorry.
Not sure exactly what you seek?
If going down wavefaces, quite straight, then the same would apply for the big kites I would think, huge range and a kite you can kill.
Most foil kites can be flown to the edge yes, but they also have this bad behavior of pulling way too much, when you get speed, meaning down a waveface it is not good
But if you get a low performance foil kite, say a single skin (like the Peak4 or ConceptAir single skin), they tend to be able to be killed, and they dont have peak power like other foil kites.
They can also hang so you can get ashore if wind drops to almost nothing, another advantage.
But they all turn like dogs, thus quite important what you seek with these big kites for a surfboard?
Have you considered hydrofoiling?
Your conditions seem perfect for this.