I know this is a necrobump, but A+ has changed quite a bit since 1999...
Would I ask a prospective instructor to take the entire course again? absolutely not! In fact, if an employer told me to take an entire A+ course, just to teach a course for that employer, I'd tell them thanks but no thanks, and withdraw my application.
the TTT would be nice, but that wouldn't be something I mandated... but it should be in the resources I profile him)
What I would do is require any new instructor to hold a current cert for the course they are going to teach (and GFL and ce certs are not the same). I'd provide the voucher so he wouldn't have to buy it himself, but no one should be teaching a course unless they have passed that exam. When I started in my current role, my director told me I needed to take the ITF exam to teach the course. I have ~20 years in IT... and passed the exam
here is my perspective: if he has 20 years of experience, and he is up to date on his knowledge, then he should have no issues passing the exam.
If he can't, do I really want him teaching a course for an exam that he couldn't pass?