Should I point out typos on students' important forms that I am signing?
I would point out the error, especially if you have a reason to believe it will be taken into account in some nontrivial way.

I don't really understand why doing this goes against the student's "self-reliance".  I point out errors of this kind in papers that I am refereeing, for instance, and when people read my own papers or course notes or whatever, they sometimes point out my own typos including spelling errors.* I don't think that either I or these other adult academic professionals are failing to show self-reliance.

*: I do all my writing on a version of LaTeX with disabled spell-checking, so I have to spell my words correctly "the old-fashioned way".  Mistakes do sometimes creep in.  I could be setting things up better, but anyway the New York Times occasionally has spelling mistakes.