> in in support of "BRC-20" tokens, which is Bitcoin's feature reduced version of Ethereum's ERC-20 token
It appears that BRC-20 is primarily affiliated with Calvin Ayre, the person backing "Bitcoin SV" and the conman pretending to be the creator of Bitcoin -- the three main entities connected to it are all funded by Ayre and they've been bragging pretty loudly about their disruption of Bitcoin ( https://nitter.it/B2029org/status/1655611301412982784 ). I've heard speculation that the attacks are either a marketing pitch for "Bitcoin SV" (e.g. create congestion on Bitcoin then pivot to the unauditable centralized BSV blockchain, which always has room cause it's easy to scale centralized systems) or an effort to get Bitcoin community members to propose protocol changes to block the flood in order to substantiate the allegations in either of the Ayre-affiliated 6 billion dollar or hundreds-of-billions-of-dollars lawsuits.
I'm not aware of any previous active Bitcoin developer that had anything to do with BRC-20 tokens, if you know of any I'm sure the bitcoin community would be very interested in learning of it.
> changes recently that allow much larger transactions,
Unless you are referring to increasing the capacity of blocks back in 2017, no change to the consensus rules that allowed larger transactions has happened. You can easily verify this for yourself by starting up an older copy of Bitcoin and observe that it accepts everything fine.
In any case, this "BRC-20" crap is mostly only embedding 89 bytes of data ( https://twitter.com/jratcliff/status/1655669410206457865#m )-- it doesn't need any larger transactions. It happens to stuff it into the most recent transaction type, but there is no reason that it couldn't put 89 bytes of data into pretty much any other kind of transaction.
I think the false claim that BRC-20 was made possible by recent changes is mixture of confusion and an intentional deceptive cooperation cracking move, intended to direct even more harassment at project contributors but it's just not true.