branches snapping is something you need to learn what size of stem is expected to snap..
This comes down to a little trial and error. Buds can feel dry,but moisture takes longer to move from internal plant material to surface plant material at a slower rate than evaporation. So, once it feels dry on the outside, you always need more time beyond that.
If you seal it up and the surface of the buds regainst elasticity and feels 'soft', you know there was still excess moisture in the buds and you need to remove them from the sealed container for more air drying. So, if you think it is dry enough, put it in a container and check back in a few hours... and then a few hours after that, lol. If the plant material remains consistent, it's fine at that point.
2-way RH packs are a great thing to use. Boveda maintains a consistent, as-advertised RH%. these have limits. They can't just absorb endless amounts of moisture or release endless amounts of moisture. you can tell what is happenin by whether the pack is gaining or losing weight. It gives some room for error but cannot mitigate wet buds in a closed container.
I wet trim and cut down larger stuff to equally sized buds as best i can for a more consistent drying rate. My room is less than 70F and 60% rh. it takes 12-14 days. When i feel them dry on outside, i know it has 12-24 hours longer to go. You will learn what is necessary over time if you pay attention. be systematic.. find a trigger that works consistently.
if it's on a drying rack or hung for a little extra time, it's not much of a problem as long as the drying area's climate is basically like a humidor. Exposure to the atmosphere does increase degredation, but that's more of a problem over the long-term - months or years of storage.
If you smoke it all within 3-6 months, 1 extra day of drying will never be noticed. Maybe, if oyu store it for 2 years, you could tell the difference between buds that had an unnecessary extra day of drying than buds that did not.