You might also consider a brand that has truly worked out the challenges in WSMs -SAVAGE
They departed from their standards for WSMs, and their adjustments can be your lessons.
And don't forget --Savages shoot--
A Savage WSM action:
Larger barrel tennon, and shank
Controlled round push feed
Standing blade ejection
SS, accutrigger, floating bolthead, fine 20TPI barrel threading, barrel preloaded AWAY from boltface, plenty of aftermarket and DIY potential.
Try finding all that in a 'custom' 'aftermarket' action. No, forget it, you won't.
I have/had a Savage WSM action, unfortunately held in limbo at the Canadian border(for 8yrs now!) & overall it was one of the finest actions I've put my hands on.
I've had a bunch of BATs, and love them. I use one now that I had made special for 6.5WSSM. It's an RS(magnum repeater they no longer offer) but single shot and with CRPF/blade eject, and bottom/bedding recoil lug, Jewell trigger. It has the larger magnum threading.
But as sweet as it is, it still lacks Savage's fine threading, barrel nut, floating bolthead, and DIY barrel fitting.
I can't just have barrels made on the side & replace when ready. I have to take the gun out of service to send it off to a gunbuilder for new barrel fitting... Back of another line....