well Tobirama mentioned something about the special chakra in the Uchiha's head when they get MS.
so maybe it depends on what they think about . Lol
The thing about Obito is both his eyes were in 2 places at the same time when he unlocked MS
and he was also engulfed / combined half with Zetsu.
At the summit Oonoki said Zetsu mustve used some time delay jutsu after they thought he died , but appeared out of nowhere.
Maybe Senju/Uchiha power combined. & maybe Oonoki meant kamui s/t
Zetsu can slip through things (earth) so combining him with Uchiha probably developed Kamui that way.
s/t jutsu is kind of like being in two places at once just like Obito's MS eyeballs.
you got a point there , i agree.
thank you

I also forgot to add
Obito first awakened his sharingan and skipped 1 tomoe and went straight to 2 tomoe.
Skipping tomoe when you first awaken sharingan is a big deal since no one else has done it.
He also went from 2 tomoe to 3 tomoe to MS in one moment. He didn't have any time spent on 3 tomoe really.
Zetsu said Madara chose Obito , so maybe Obito had a Zetsu inside of him when he was too young to remember.
Enhancing his power and enabling him to skip tomoe . Or maybe Obito was just that powerful.
Also Obito could see through Kakashi's eye while he wore Zetsu & Zetsu can communicate telepathically.
Maybe all of that ties into his power of s/t.