QFT. Invincibility frames or no, Wake up SBK isnt always your best option. ESPECIALLY if UOH (which is obviously universal…) can knock you out of it. Consider this, you waste (yes, WASTE) 1/3 of a bar of meter, and your opponent presses two buttons, uses no meter knocks you out of it, and sets up an option select UOH super.
edit: personally, I mixup the wakeup with all of Chun-Li’s ex moves and Crouching RH. But, no matter the matchup, I’ll save ex SBK as an Anti air mixup instead. It really throws people off, especially if they’re parrying all of your HP and c.RH anti air.
REedit: If playing a really aggressive Ken player or something though, and they fall into some sort of Mixup pattern (insert generic Ken mixup.) feel free to ex SBK for guaranteed damage. Bait a sweep or c.MK or something and then punish freely. Just watch out for UoH as part of the mixup.