If you stop cycling, do you lose your size gains?

[LGXDownunder]

I'm not quite 15 weeks post op, but as I've gotten older my mantra for all things related to physical health is "move it or lose it".
Whether that be knee replacements or penile implants I believe that regular exercise is necessary and a good thing.
I don't yet know what my cycling regime will be in the future but I plan to keep exercising the implant regularly regardless.
Paraphrasing what someone said in another thread, you don't get an implant to go around with a flat tyre.
Thinking about what I've read or heard from urologists, to prevent atrophy you need good blood flow to the penis.
You can get that through nocturnal erections (which many of us no longer have), pills, injections, VED use etc, or an implant.
If you no longer inflate the implant at all, then I would assume that you no longer promote enough blood flow to prevent atrophy.
So I would think tissue such as the tunica albuginea could start to shrink etc. How that would interact with the implant cylinders I have no idea.