If you think SE is going to have someone go down a list of what each addon does in order to decide if this give an advantage or not you are delusional. To then say "yes this one is ok and this one is not okay"

"so what does this one do" oh it changes the shades "anything else?" We don't know we did not create the mod.
"perfect lets look at the next mod"

For ... Every ... Single ... Mod ... and addon.

Rule of thumb ...
was it created to be used for FFXIV specifically? Yes, prolly should not run around yelling you use it.

Half the forum acts like they 100% constantly share their screen, its client side, use what you want and be quiet about it.
There is no grey zone and there is no slippery slope its all "forbidden". You have 3 options,

1: Be a saint and use nothing
2: Use what you want and be quiet
3: Cry on forum