Repeat after ME.
What is the Susanoo made out of?
What does the byakugan see?
What does the GF do?
Again the byakugan has the best insight, you literally see her have her eyes active all the times she solos Sasuke, then she deactivates it.
lol I wonder where the 3T is?
My point still stands you can't give or call something a technique of such and such if it isn't a technique of such and such. It's not a GF technique, it's never referee to as a GF technique the Hyuga who use GF technique don't use the same technique. Even in a weaker form instead they made a GF technique which is similar to it because they can't use it. From all the above its evident it's not a GF jutsu.
Kaguya's other feats aren't sharingan feats and can't be called as such they're also kekkei mora techs.
Ps. Who's Natsu Shazneel my avatar is of Acnologia(the king of dragons) not Natsu ( the king of ass pulls).
GF is the technique of using on'es chakra to put their chakra into that of their enemies.
Using every chakra point to expel chakra happens when they unlock their byakugans as seen via Hima.
Again names were just given during the shinobi age.