I feel confident with Ti related aspects (or at least what seems like Ti), even though it's not in my ego function.
And being confident with Ti also doesn't mean it's in their ego. All logical types are good at it.
I can see SiTi though (this is valid according to Gulenko if you trust him), but Ti as an auxiliary and thus less developed, not a leading function. But this is out of original Socionics I guess, so...let's put it aside.