This gives a good overview of where all the nodes are at right now. Interesting, the way I am reading it is BU nodes at 33.1 %
http://xtnodes.com/No. Why are you preaching something which you do not even understand? BU nodes are at ~8% at best (see here:
https://bitnodes.21.co/nodes/), or more realistically at 2% (see here:
http://luke.dashjr.org/programs/bitcoin/files/charts/software.html).
BU/BTU is a absurdly stupid idea that provides even more centralization incentives and power to the mining cartel. Is this what you mean by 'sounds great'?

But the big pools can fork it almost when ever they want, no?
They can fork into an altcoin whenever they want to.
How would it be possible to stop it to be the main chain?
Sound great was meant has a marketing concept. fundamentally or the blocksize never change and the fees align or the system move to what ever. I liked the idea of having modular blocksize, but dynamically would be better... and then why mine or pay fee at all? PoS.
Look :
I conducted a study of the % rate paid by the pools to the miners.
Look, the usual pool takes 0.3-1%. The amount is used as payments on server bills and profit to owners.
A pool like the Antpool pays the miners up to 20%. This means that they work at a loss!
From this we can assume the following:
- They work at a loss because they are subsidized by bankers - supporters of Bitcoin Unlimited and special services (as you know, BU will lead to centralization and make bitcoin controlled as paypal)
- Sooner or later, owners of pools of extra-paid miners may not pay a reward to the miners
Owners of large pools to spit on bitcoin. They will pursue their interests.
My conclusions:
Do not support large pools! It's a scum! Time bomb for bitcoin!
!
operating the pool at a loss, concentrating the maximum hashrate... who knows?!?