I’m developong mostly Vericolor from the 80s and 90s but also some Fuji NPS and NPC from the 90s and early 2000s. My understanding is that the new final rinse became available in 2000 and replaced the Stabilizer III, which was necessary for Vericolor films and older (I don’t know about Fuji films though). From my reading, the issue is not so much the present - my negatives are coming out fine with the new final rinse - it’s the longevity of the dyes that degrade more rapidly without stabilization from the formalin that is only present in the Stabilizer III.
This thread has some good info:
https://www.photrio.com/forum/threads/c-41-stabilizer-usage.44489/
Those pills look interesting, though I don’t see that they contain formalin. Would they accomplish the same purpose more safely?
Obviously it would be nice not having to deal with formalin at all, but I’d like to know that my negatives are going to stick around for a while without going bad. Or maybe a raw file from a scanner is the really the only way to preserve these older films