You're welcome. Here's some homework to do that's not weather dependent. Better to do a run through of the process before you have gelcoat with a limited working time.
For this mockup of the process I used a piece of particle board and latex paint. They do not act as gelcoat on gelcoat would as particle board wants to quickly absorb the paint. But the process is the same.
I used a piece of mylar for clarity but heavy poly works well. Heavy as in the kind used as vapor barrier, not dry cleaner bags. Tape all round the edges and hinge it down. After the gelcoat is dapped in the crack you put your finger on it and roll it upwards expelling any air.
You can see one of the cracks widened out and the top edge rounded off a bit.
The secret to an easy and perfect repair is the amount of gelcoat you put in the crack. Too little, #1, and you'll have to give it a second coat, #3 would be usable but the extra amount just takes a bit more wet sanding to make a perfectly flush repair. The center section of #2 is the perfect amount. In many cases when I've had that situation with filling I didn't even have to do anything more, depends on how visible the repair area is.
I've given demos using real trailer f.g. cutouts and real gelcoat and, as I said, paint and hardboard follow the process but don't act the same as gelcoat on gelcoat. The real stuff is easier.
Ron