Don't chase him any more... or he may become aggressive towards you. In my experience, chasing escalates the situation. And I'm not trying to be seen as part of the pecking order. If you need to... look into some rooster training techniques, but the crowing AT YOU... that's a sign of things to come.
First thing in the morning and last thing in the evening is when the boys seem to be the randiest.

Sometimes I will add my boy from the stag pen in with the ladies after the morning rush has passed. And I don't let my stags out until about 8 Am, as a courtesy to my neighbors for one. But also because their is less activity at the fence once the girls have dispersed from the feeding area. I'm not sure if it helps or not. But chickens are stupid... given the chance he might mate her to death... it's been done. You are already aware though and so I'm sure it won't go that far, assuming she is still strong and healthy... and I think that is how she sounds by your description.
They look lovely.
If his age is the same as how long you've had him... he is facing another maturing point probably right now... hopefully it shapes up good for you both.
Yes it's true that hormones are starting to rage more as light is increasing. I don't know how the males hormones are controlled but even if it's sensing pheromones from the ladies and not light driven like theirs is... then it would still correlate to spring since egg production does ramp up in spring. And I see my boys go extra wild with excitement when they hear a lady sing her egg song. They know she is fertile and they want desperately to spread their seed to her. Fascinating creatures!