This is a lot of concern about about the balance of a full sus, but there isn't such a concern about hard tails?
I've got 140 front and 120 rear, and the bike doesn't feel unbalanced, but it's fairly progressive on the front, the MRP ramp control is set to about 2/3.
This. My Transition Scout was designed to be 140 front and 125 rear. Was the most fun bike I've ever owned. Could whack the fork up to 160 for the Alps too and it was still very good. Forks more important than rear end IMHO
My concern was with the balance of the bike - a 140mm fork with a 120 rear is gonna be weird
Longer forks also decrease reach and slacken the seat tube angle, albeit by small amounts.