Exposure does build tolerance.

Yes sir. If I ever become a CFI I'm going to start practicing unusual
attitudes nice and early in the student's training rather than a week
before the checkride!

This is another good example of why it's so important to use a good syllabus.
The Jeppesen syllabus I've used includes unusual attitude recovery in lessons
1, 3, 5, 6, 8, and 12, and in three stage checks as well.