okay, now that i've had a minute to sit and think, i return with ideas! if they don't work, feel free to say no and i will brainstorm some more! the first is that since ryan arrived at the station, even though general care isn't his area of expertise, leon could come to him from to time for care for his degradation. the a.c.e. medical center includes robin, who leon doesn't want to worry too much for various reasons, so you know, don't mind him hiding his symptoms.
option two, maybe leon could have been a part of recruiting ryan to a.c.e. leon does a lot of research on anything remotely related to piloting, which could easily include cybernetics given the mind-to-machine connection. he could find ryan's old publications on space-jstor and reach out to talk to him about it, and then encourage him with aggressive positivity to join up with a.c.e.