I think when they foxtail they are done. The new calyx and pistils keep building and you can keep checking, but they never look finished, but I’m fairly certain that further in they are.
I was told by other forum members that the smoke may be uneven because of the mature and newly formed trichomes being smoked at the same time. One member says he cuts the top of the buds off.
It’s odd because there hasn’t been any new growth in at least 3 weeks and no new white pistils developing for longer than that