I grew a shitload of vellus hair on my temples and hairline on minoxidil. The stuff is more areally dense than any hair on the rest of my head, LOL it's so cruel.
After using spironolactone a couple months it looks like more of the hairs are now growing longer or thickening. But I put so much sh*t on my head, who knows.
I am sticking with it, I think it is helping but nothing definitive.