I've been practicing some on releasing pressure off of the B and hi E strings and I've got it down clean a few times. It's a really tiring technique to practice so I'm taking breaks inbetween. Luckily I've gotten better at handling frustration when it comes to learning. Just taking a few deep breaths before trying again until I get it right.

I also do what you do icebreaker when strumming open chords on my acoustic. But it's way harder strumming up from the G string than it is from the hi E.