“Bitcoin Unlimited” miners are signalling, right now, to keep blocks small, and keep fees high so they can make money.
Why would they back a proposal that removes 15% of their profits! I would be happy with a “max block = 105% of median” approach. 2x median is ridiculous, since this eliminates the fee market… every simulation shows this.
But 1.05% (or even 1.01) allows the network to run, on balance 95% full, which has been shown encourage a strong fee market. Plus, it allows block sizes to shrink, so layer 2 solutions don’t eat miner’s lunch.
This allows for very gradual scaling, and makes it nearly impossible for miners to game the system. But current miners would block it straightaway! Because it would lower fees.