I'm afraid Fi is just too random, dizzy, and wishy-washy in its subjectivity. Or at least (before I get in big trouble as usual), that's the impression Te gets from observing Fi in action. And so any sign of this function in the Te is squashed out of existence - almost.
And yet the best way to get through to a Te-dom is, in my experience, via the Fi-inferior.
There is a feeling mechanism present in this type. You can see it in their eyes when they look away and suddenly change the subject. Sometimes they will fall for a good sob story, but not too often. When interacting with Te-dom, it's like walking barefoot over a hard-wood floor, then occasionally stepping on a soft spot where the wood might be rotting away. That's the signal that Fi is not so thoroughly buried after all beneath the tough-as-nails exterior of the type.