For the lay people it comes down to it using widescan when it should not be able to, correct?
Yes, in part. There's two layers:
1) using Widescan functions when the client should not be able to (can't open map at all in either Limbus zone)
2) being able to go
much beyond widescan range, to request updates about any arbitrary mob that exists in zone, whether it's dead or alive, at any distance, and whether it appears on widescan or not.
Putting aside 1 for a moment, the packet used in 2 is normally only sent by the game client when you use the Track function of Widescan - so you can only select a mob that has already appeared in your Widescan, limiting range to w/e range your job has. Mobs beyond that range are inaccessible, and you're rate limited, the client doesn't let you spam that request (need to cancel the previous one). And certain entities, like ???s and homepoints and many more, do not appear on widescans at all in the first place!
This is nowhere near close to gearswap injecting equipset packets faster/more precisely than the game can, or using weaponskills while not engaged[*], it's a couple of orders of magnitude more exploit-y. And detectable. And will very likely be patched if it becomes too widespread, like warping to locked homepoints was, but that's just my prediction that could be wrong.
My issue, which do note that I bring here personally and not as voice of the windower team, is not with the function itself (other very common addons do much worse), it's with a disclaimer that only says "inject packets", sounding innocent like a million other addons that also inject packets and are very, very much innocent (dunno, the temps addon, or MAGA for Oseem augments, or the already mentioned superwarp).
It is not. It's a full on exploit.
[*] which for the record only happened as a bug and is only still there for legacy reasons, it's been debated a million times if it should be removed