What is the effect of CBT/Ballbusting on Testosterone production?
Let us assume that the sub does not have catastropic damage from said activities, and can have children etc. But still, ballbusting/CBT would kill testosterone producing cells. Can these cells regenerate? Or are they like brain cells which (mostly) do not regenerate?

What is the (permament) drop in testosterone production that can be expected for a typical player?

Related: what are the horror stories you have heard about guys who have had permanent damage from ballbusting: lowered testosterone, infertility, erectile dysfunction, loss of sensation etc?