Logistics of letters of recommendation during gap year(s)

S1 has spent the past year on medical leave of absence from college due to mental health isues and anticipates being out one more year before transferring to another school. He completed freshman year before going on leave.

He is planning to reach out to last year’s profs for letters of recommendation before they totally forget who he is, but doesn’t yet know where he will apply or how many LOR’s/copies he’ll need. He asked his academic adviser if she coulld hold them on file but she said she can’t.

She suggested having them mail multple copies to him, each in a sealed envelope signed across the flap. Is this the best plan or are there other alternatives? @Hanna, I’m tagging you on this because I imagine you might know the answer…

Thanks