They definitely advertise as made in mexico. I don’t think they’re Chinese boards.
Might be other woodshops in Mexico now so the list could do with an update if anyone had any other info, apart from the known three BBS, PS Stix and Clutch.
Usually BBS (different concave and dimple dot), PS Stix wtih serial numbers on all their boards, or even Clutch without their letter / number board stamps if they were specifically saying "Made in Mexico" but as per every request for any more info, it is unanswered, compared to every other question people ask, from looking at their more recent posts.
They were based in Canada when they first started too, everything there including woodshop, presses, etc.
Looking back through their older posts, the last time they posted anything about actually pressing boards was back in June 2020, then a post with molds for sale. Could be that they moved to importing blanks over pressing their own boards, but either way it is not a worry to me.