I was on finasteride for about 6 years due to BPH before I started spiro. My urologist recommended I continue at that dosage for another year while spiro and estrodiol slowly shut down my testosterone production.
Once I stop trying to make T, there won't be anything for 5-alpha-reductase to use to make DHT, so blocking 5-alpha-reductase with finasteride won't be necessary any more.
It did change the nature of the fluids in ejaculate, but that didn't matter to me, as I wasn't interested in using that hardware anyway. My hair loss stopped, alas, too late. I still have Norwood Class VI pattern baldness, so my hair comes in a box these days.
It is best taken on an empty stomach, so I take mine right when I wake up, before breakfast. Spiro can upset the stomach, and is better taken with food, so I take that right after breakfast and dinner. (Split dose per doctors orders, helps slightly with blood pressure control.)