Blind Grav is just blind luck (ha) whereas intermission 1 requires you to actually know what you're doing. You can probably optimize your strategy for Gravitron but just by trial and error you will get through it eventually, even if you're blindfolded. Keep in mind also that after a certain number of deaths it does actually get easier, so the more you die the easier it gets (up to a certain point).
(wow, BLIND luck? ha. ha. nice one.) anyway, idk if anyone posted this already but here is the link in case anyone can't find it... https://www.speedrun.com/vvvvvv_category_extensions#Blindfolded It's already got just about every route you could ask for, I think. Any%, no TJ, no OoB, glitchless, and 100%. (But not credits warp or no death mode, because... come on, that's going too far.) :)
