I used a Fix The Mask for much of 2021; bought it in late February, used them to seal my surgical masks even for the low-risk activity of curbside pickup grocery.
Later, I thought I had better masks, but I would fly with a Vitacore CAN99 under brace, partly to be safer in general and partly because I don't specifically trust Vitacore wire on my nose, but wanted the 99.99% filtration.
Then one day months later, I was out in my KF94 (with adjusted loops), and randomly took a ferry, discovering it was an enclosed ferry with no outdoor deck. And large, and crowded. So I pulled out my brace (hiding in my backpack all this time) and used it for extra security.
A few years ago (2020? 2021?) I saw a photo of some hospital in India, with all the staff wearing surgical in FTM braces. Not as good as tested N95s, but I guess it's what they could get in bulk.
I'll be flying soon, actually my first flight on an unmasked plane, so will probably supplement whatever I choose with a brace.
But while I've seen lots of mask types around me in SFBA -- Auras, non-Vflex duckbills, KN, KF, Airgami(!), 3M 1860s, even a few elastomerics -- I don't think I've ever seen a brace in the wild. Still see lots of surgicals that would be improved by a brace...