I was thinking this since I first read about the adaptive triggers on the DualSense controller, but I was never sure how well it would work. The the double-tapping of the triggers for WXHB isn't ideal, but before the DualSense, I saw no other way to implement it. Now there is: half/full press of the trigger for "normal" XHB and WXHB. The adaptive triggers are capable of providing the necessary resistance and feedback.

I'm not sure how well this would work in practice, one has to try. Unfortunately, there are no drivers for the DualSense yet to experiment with this at home. However, if you start up Astro's Playroom, the very first thing it does is something in exactly this line. More importantly, Returnal is coming out soon and uses the triggers in such a way: half press for normal fire, full press for secondary fire. Previews of Returnal agree that this works great.

So, it would be nice to see something like this in FFXIV for the WXHB.