Ran a few Deca/Dbol/Test cycles in my early and late twenties without any noticeable change in hair quality or density. It could be that the damage was so minimal I didn't notice a change at the time. Ran a cycle in my early thirties and the hair started falling out in handfuls almost immediately, even after I stopped.
Now I keep the hair cut tight to the scalp and take Propecia and use 2% keto in hopes of holding onto what I have left. I still have a lot of hair left and an intact hairline. Keto doesn't dry out my hair at all and like you, I keep it in my hair for thirty minutes or so. If you can get your hands on it, use Extina. Extina is a keto foam and it was so easy to apply and it didn't dry out my hair or scalp. Plus, you don't wash it out, which allows the active chemical to better penetrate the scalp. The big draw back, and the reason I don't use it still, is price. There aren't any generics for keto foam and it is pretty pricey.
I'm glad you seem to be keeping your hair using a similar protocol to mine. I'd be a lot more willing to run a cycle again if I knew I could keep my hair. I know, I know; i'm a pussy who should just shave it.
How is the topical spironolactone working? I've been thinking about adding it to my regiment but unsure if it works well. Is it expensive?