Does it make sense to apply Minoxidil behind the hairline?

[Shmanky]

I am applying 5% Minoxidil to my left and right temples, to the edge of my hairline, and also behind the hairline on the "crown" area, which is the area towards the front of my head, between my temples. My question is whether it makes sense to apply minoxidil to an area that already has hair. I want to apply it on my crown because I've noticed that the crown area is less dense than it used to be, and less dense than the sides of my hear near my ears. I'm also on Propecia.

 

[HighOnDHT]

If its less dense then you will eventually end up bald there, its a good idea to attack it early, this is what I am doing.