Handwritten keys and ADA compliance
ADA requires you to accommodate the students you have.  If you have a student who cannot read the hand written documents because they have a disability, you must distribute them in a way the student can access them.  Your disability services office should be able to advise you.

Providing searchable, typed documents would help some students with disabilities and also some students without disabilities, so it would be nice to do.  I recommend the universal instruction design approach.

A UID book