My experiences with stabs (having had a load of different sizes, from 170 to past 300 cm2, is:
The bigger the wing, the smaller the stab I prefer, for waves and fun, as much more lively, in particular in turns.
For the WaveXL the difference is not as huge, as with the 1200 wing, but of course can be felt.
A tad bigger stab gives a more smooth driving feel, also nice, and if you want to jump (I dont do that much) it also feels a lot better for some reason, it can track and you can load.
Using a 175 cm2 (very close to the XS2) right now with the 1200 wing, always.
And typically a 233 cm2 stab with the waveXL wing, works just fine.
All my bigger stabs has been cut down now, or sold, these sizes works for me.
I would say an S2 stab which is 245 cm2 works great as an allround, but you could get a smaller if you want it even more lively, or cut it down if you are good with tools and eyes and maybe resin for shaping the profile "almost perfect" again.
Supersmall stabs, I must say I dont believe in, meaning 100 cm2 or something, too close to a stabless, which I personally dont believe in - but some do, so individual.