You could end up with a network with a multitude of different excessive block and acceptance depth settings. That sounds like a complete clusterfuck to me.
or
pools see it can be a cluster fuck and dont go passed a limit unless majority of preference says its not going to be a clusterfuck
A simple block acceptance size with an acceptance depth of '1' achieves that without the unnecessary complexity.
the blocks are "accepted" EG say a block A 0.251 received and also block B 0.249
(both accepted because they are both under 1mb consensus)
both sit there accepted.. but not set in stone.
yes some nodes are happy to accept blocks upto 0.5 some are happy with 0.25 and some are happy with 0.25 only after 6 confirms.
but all are holding both blocks until conditions are met.
the acceptable depth is the deterrent.. for pools
it adds a bit of risk to the pools to not push forward too quick, because nodes may reject them if other pools are following the node 'preference' majority
pools wont want to risk going to 0.26 unless high majority say its ok. because their is a risk their 0.26 block may get rejected if the majority dont want anything above 0.25
thus if the other pools were building on block B.. A will drop off once B gets its 5th confirm
however lets say the 'majority threshold was 75%
if there was 75% acceptance of 0.3 where by looking further at nodes its seen 80% acceptance of 0.25
pools would work out the risks of going to 0.3. by looking at the acceptable depth of the group below 0.3mb.
if everyone had only 1 AD then pools will say yep very small chance of orphan risk going to 0.3..
but if there was AD12.. pools may say, hmm maybe best to stick with 0.25mb and re-assess later as there is a chance that if i make a 0.26mb block other pools may not. due to such a high AD
(yes im using low numbers of blocksize so people can imagine dynamics in a scenario of 1mb consensus but where nodes had dynamic 'preference' below that since 2009) thus nodes having more control over what pools move to.
(please dont just take the reddit doomsday scenario rhetoric as gospel. do proper independent research)
remember all these blocks are still under 1mb. so its still going to be just 1 chain. in the end. its just a way to deter pools from jumping the gun rushing to 1mb 2009-2017 by knowing some nodes prefer only 0.x..
and pools become more obliged to follow node preference because their competitors pools may only build ontop of node preference.