If you are genetically inclined to MPB, it may very well be worth your time to use finasteride to mitigate your genetics.
I have used finasteride for over 17 years now with out missing a day. I've never had any issue with my gains and for all my time using finasteride I was training naturally. I started using it in 1995 long after I gave up AAS.
I actually had a gyno issue from my previous steroid use. I had it removed and finasteride never casused an issue for me with it.