There seems to be a lot of conflicting perspectives out there surrounding the degradation of mushroom genetics over time and I was hoping people here might be able to point me towards consistent information.

Specifically, I'm curious about the longevity of mycelium used for grain transfers. I've been doing g2g for the last few months to keep everything going and so far I haven't noticed a drop in performance, but it's been a concern at the back of my mind. I still have most of the original cultures on agar and was thinking of "restarting" with those, but is that really necessary for a hobbyist like me if I'm not churning out large amounts of spawn?