Q Light Controller+

I used a standalone app called LEDFX to control a string of addressable LED's, the app gives some advanced sound-to-light functionality

It would have been nice to control it from QLC+ and whilst I can see mention of QLC it in the code of its API (as if it supports it directly), I cannot see mention of it in QLC's or LEDFX's documentation

https://ledfx.readthedocs.io/en/master/ ... ea=default

I am not aware of every software/hardware in the world that has something to do with QLC+.
I have also never heard of ledfx before.
The API you mentioned looks like LedFx can control QLC+, not the other way around.