There is nothing stopping all the miners from simply dropping the btc1 fork code and just using core after segwit is activated, and not all pools actually signed the agreement.
Pools were not the only ones signing the NYA agreement. Hard to believe every NYA signer going to toss his reputation by not honouring the agreement. And we are talking about the most important Bitcoin companies here...
https://medium.com/@DCGco/bitcoin-scaling-agreement-at-consensus-2017-133521fe9a77Most bigger pools/companies use custom software, so the core vs btc1 code is not relevant here, what only matter is being compatible with Bitcoin, like accept up to 2M base blocks in about three months.
Your last sentence contains very wise sense: Custom Software
That's what we need to head to.
Gedankenexperiment:
Do we need software at all?
Think of the Monopoly Game - The rules a very simple written into a White Paper
Who / what enforces the rules? > there is no tech impl needed!
There is just a strong agreement needed between more or less equal players that will all benefit when all play to this 'mental' rules.
You trust old big player a bit more since they keep the game on track.
It there is a single one getting too big -> all others will exit this game.
So players see them getting too big , needs to shrink i.o. the keep the game up and running into eternity...
>>>>
The tech code we need could be a very very thin one -> minimum protocol level