New B4 Strats (HUGE for Any%, read description)
Short explanation: this makes bad paint viable, removing the need to reset 50% of runs to paint.
Long explanation: This makes bad paint only a couple seconds slower than good paint. Compare good paint vs new bad paint route:
Good paint goes Wrap Around the Corner, Redundant Power Supply, The Right Angle.
Bad paint goes Redundant Power Supply, The Right Angle, A Box Up High.
Notice how Wrap Around the Corner and A Box Up High are both red L sigils, so they're interchangeable, and you can pick up whichever is fastest.
Back to the comparison - both routes are essentially the same speed in going Redundant Power Supply into The Right Angle, so we can remove that from the equation. The comparison is Wrap Around the Corner on good paint vs A Box Up High on bad paint. Obviously WAtC is still a bit faster because of walking time to ABUH, but the difference is actually not run-killing now.
Implications for the rest of the paint route are pretty interesting too. Set 3 in A6 is noticeably faster than any other, so you're making up some of the time you lose in B4 there. Set 2 is still not great, but it's runnable now.
This, at the very least, makes Set 3 viable for the most competitive times, and that's 25% less resets due to paint. 50% if you take Set 2 as well.
Add-on: MousseMoose has found a tree climb, similar to the one in The Right Angle, for Wrap Around the Corner. However no one can seem to replicate it, and he is moving so he can't record easily. It looks very FPS intensive, and I can't replicate it, but maybe people with better machines can.
As for how to perform the trick themselves, simply hold the direction against the wall and spam jump while looking completely down, and you should have an easy time getting them.