Lyman's 6th edition (the version published this year) has lots of WSF data for 12 gauge STS and Win AA hulls listed as 1 1/8 ounce FIELD loads. WSF is best for high speed 1 1/8 ounce or 1 1/4 ounce loads, after all.
I reload for trap and skeet.
So, WSF is not a typical powder for trap and skeet unless you are loading for the long-range trap games. It's a FIELD powder, as might be expected from it's name.
But, I'll sample a couple of loads from Lyman for you to get you started.
For the Rem STS hulls:
WSF 24.0 grains Win 209 Primer Win WT12 wad 1256 FPS 9800 psi
I'd feel safe subbing the Claybuster WT12 wad (CB0118-12) or even the Fig 8 clone (CB8100) in that load, if I was sure the pressures were still in line. You might be able to still make a good stack and a slower velocity if you backed off a grain or two of powder.
For Win AA-HS hulls, there is even a target-speed load with WSF:
WSF 24.0 grains CCI 209 primer CB 2118 wad 1192 FPS 7100 psi.
So, I'll agree that are fewer number of loads published for WSF in 12 gauge, but they can be found if you broaden your search.
I have looked at Hodgdons Web site,
Well, I found some 1 1/8 ounce loads on Hodgdon's site just now, like these for Win AA-HS hulls:
Winchester | WSF | Fed. 209A | WAA12SL | | 21.5 | 7,200 | 1,145 |
Winchester | WSF | Fed. 209A | WAA12SL | | 23 | 8,400 | 1,200 |
And there's a few Rem STS hull loads on Hodgdon's site too. So, I don't understand, unless you are being stymied by including a Cheddite 209 primer in your search. Seems like the existing published WSF data has not been re-tested with the "new standard" Cheddites, but there's lots of recipes for the "old standards" of Win 209, Federal 209a, and CCI 209.
good luck, garrisonjoe