Not new tech exactly because everyone knows how the FA system works by now, but certainly application that when applied correctly can net huge rewards.
Main issue I find with Fei Long in this version is being able to land any meaningful damage from CHs. CH cl.MP and cr.MP are generally going to get you a free Rekka combo but the damage and stun still isn’t great for potential risk of attempting the frame trap and reading your opponent wrong. There’s also the issue of DWU nerfing the sweep follow ups off both of these; the risk/reward just isn’t there. Another issue is being able to land Ultra without meter to make a comeback is basically only doable from landing FA crumples. Focus Attack is already a risk in open play and being down on life with need of a comeback makes landing one more and more unlikely.
The new buff to Engekishu (Toward+HK) is there to offer a new frame trap option and a way to convert into max damage, but the massive change in Fei’s silhouette makes it so that it’s hard to fool opponents. There’s too much movement in the animation and as such is easy to react to and block.
An option to remedy all of the above is to use Lv1 FA as a frame trap on the opponent’s wakeup. The change in Fei’s silhouette from neutral standing to FA is very subtle and difficult to perceive. By the time his animation has changed, he’s already about 10 frames into the startup of the FA. It’s very possible to land a CH in these situations with this. It’s -1 on forward dash (so it’s safe in general) and -10 on backdash. With the backdash variant, you are usually in range still to land U1 after the crumple. It being -10 is also a moot point; no one punishes FA backdash on reaction because it just happens too fast.
The situations where this is usable is when you need a comeback but getting more than one opening to land enough damage to kill is looking unlikely, such as when you are at a meter disadvantage. Another situation is simply if you have a read on your opponent’s tech timing and want to convert your frame trap into 400+ instead of just 250.
Here is a video showing it. I attempted it twice in this match. The first time I delayed the FA too much for the opponent’s tech timing. The second time, I adjusted it slightly and netted the CH I wanted: