Why can’t they do a CW-style best of 3 - Fri/Sat/Sun with all games at higher seed?
They don't have enough time. Such playoffs would need 3 weeks of series plus the Queen's Cup/Bronze Game. The regular season did not start until November.
I don't mind the single knock-out. The NCAA does that for regionals and some conference finals. In all sports, the conference tournament often involves all teams. But there should be a cross-over. For example:
Weekend #1:
Straight knock-out mini-tournaments in four locations.
Far East #1 hosts 4-team tournament:
Far East #1 v East #4
East #2 v Far East #3
East #1 hosts 4-team tournament:
East #1 v Far East #4
Far East #2 v East #3
Far West #1 hosts 4-team tournament:
Far West #1 v West #4
West #2 v Far West #3
West #1 hosts 4-team tournament:
West #1 v Far West #4
Far West #2 v West #3
(You could also have #4 v #5 in a play-in quarter-final if wanted.)
Weekend #2
The four winners would play in one location, with two semi-finals, Queen's Cup, and bronze game.