Best advise I think I could give would be to identify an available bear sealer and then plan your hunt to allow time to meet up with the sealer and get your bear sealed.
Are you hunting by boat or the road system? North or south(central) end of the island?
Might could have some general advice but I generally hunt from a boat so maybe not relevant.
I like mid may myself, get to far along into June and they seem to be rubbed and everything is green. But so far this year has been a heavy snow year. If winter hangs around long late May could be prime.
Also lingcod tends to open 15-ish of May, so thats a consideration if fishing as well. Kings may also still be open in May. They can shut them down or reduce limits early summer some years.
18-19” seems about average, some folks get 20”+ bears. Can be hard to get good hide and large skull in same boar. Maybe decide ahead if your looking for one or the other.
Dont shoot a dink or a sow. There are plenty to take your time and get a good one.