in my understanding, trichomes dont get " riper" while curing. at least only low grade.
because if they would get riper during curing you always have amber trichomes, or degraded THC in every weed
and if you look at cured weed under amicroscope, there are all stages of trichomes on your weed.
i would say, look for the grade of amber trichomes , and harvest.
i see no sense in calculationg how much they will gt riper.
look for dark and not to hot places for you storage ( after cured)