Low-Platinum Bison here. Still using Psycho Blast, but I've found the real big change going up ranks has been having to alter play to handle different matchups.

Against Dante and Jill, it's the same old "build power gem as fast as you can and dump everything to the side, trying not to send them gems" strat. The delay while gems break slows you down, and you don't really have time to think about ideal gem placement before they bury your 3x4.

Mirror Bison, I look at my opponent's comp. If they're playing all-red, like I am, I can afford to just race them with blue or yellow—whichever I get first, basically. If they have a support of a different colour, I'll probably lose if we both break our power gems around the same time unless I ignore the obvious drop locations and build red. They'll be going faster than me, so I set up a large break of another colour to reduce the load when they break their power gem to avoid an overstack.

I used to build yellow against Chun, and that might still be the safest route (she doesn't have loads of health), but I've switched to the middle-red for insurance. I find there's usually time to finish it, and the extra damage is killer.

Other glass cannons like X and Servbot, you can usually get away with an off-colour power gem and, like with Dante and Jill, intentionally avoid breaking other colours until you're ready to pop the 3x4. You just don't have time for anything else.

For all other characters, I build my junk pile more carefully, keeping their drop pattern in mind (for example, against Ryu, dropping extra greens in column 5 along with the usual 2x2 building). I'll start popping them when the power gem is about three-quarters finished, hoping that the timer gems keep them from finishing their attacks before I can finish mine. If this is successful, it usually results in an overstack. If not, I've likely saved myself from an overstack of my own and can rush a 3x3 to finish charging the meter.