I'm growing canary melons for the first time.

I've noticed the c.m. female flowers don't close after the early a.m. hours like pumpkin flowers. They seem to stay open for at least 24 hrs.
I've also hand pollinated several of them, only two seem to be getting bigger. Very slowly. Should I get rid of some of the others?
The vines are 2-3 ft. long Should I stunt them to encourage the melons to grow?

Any advice would be greatly appreciated.