Few pointers (I suppose advice with EX2+ insight…):
 Some info on dealing with the Armor effect (once the Gougi skill is activated). If you know that the opponent is going to take the hit, and if your character has a cmd grab, you can cancel any attack you do into a cmd grab (preferably a punch starter), resulting a cmd grab combo. Certain type of normals should viably work, but the few things to avoid includes certain kick attacks as a starter (such as Low Short), since it likely pushes the axis box back, therefore causing a reelback effect with the hurtbox (affecting throws) as a result. This has potential for whiff punishing purposes via run cancel.
EDIT: It is risky in general… but can be rewarding (especially with some characters like Shirase). The safe auto-pilot way to handle this is just doing any throw while having momentum, or any attack - Sweep ender (Low Short - Low Forward - Sweep OR Low Short - Sweep as two examples).
 In clarifying the unblockable guard attack (once the Gougi is activated), even though the demo lacks record options for proper testing, it might still be similar to the SFEX2+ frame data in theory. Afaik, in most cases, the UB only has 1 active frame. However, SFEX2+ has a system that overrides the potential of meaty UB being such a hassle to deal with, and may likely be treated the same way in FLEX. To understand by how much, assuming it’s universal (through testing against Hokuto), the invincibility for the UB Guard Break in SFEX2+ lasts for 7 frames on wake-up… so no matter what action the person does on wake-up (such as an attack, jump, block, throw and more), it should counter the UB Guard Break in most cases if it fits within that threshold accordingly. If this invincibility rule applies to FLEX as well, then the same course of action on defense should apply.
[*] It also brings up another point, wake-up invincibility. Again, it is hard to factually test without the recording function/proper video analysis. In SFEX2+ for example, there is a total of 1 invincibility frame on wake-up. What that means is that it is “possible” for a 1-frame grab to counter even a meaty attack (grabs have 1 frame start-up in SFEX2+, unsure if it’s like that in SFEX3/FLEX, maybe @ShinjiGohan knows)… however it’s not a thing in most cases. Most normals in that game and even FLEX (like the first bullet states) has a reel effect that will push the axis box back, including the hurtbox that corresponds to throws. Here’s an example: Hokuto’s (and likely Shirase’s) St.Strong in the first few active frames has little/no reel back effect, and can be thrown on wake-up… but, Low Short and Low Strong does. Keep in mind though that it might not work in most cases when considering the new running cancel mechanic, which might push the hurtbox towards the opponent due to the forward momentum.