a stem snapping depends a lot on the size of stem you are trying to snap.
you can begin cure, then check on it 6-8 hous later.. if the outside is again soft and clearly moist, pull out -- how long relative to how wet it is, then repeat that process.
2-way humidi packs make it easier, but they do have limits as to how much they can absorb - can weigh them and find that point..
integra boost sucks. don't use that brand. RH never matches what product says. i put 12 67g packs in a bucket that requires 2 to 4 packs and they still don't do a good job. boveda is far superior brand of the two. their 55%-59% (i forget what it is exactly) and 62%. if you like things a bit stickier, do the 62.
i wait for the outside of buds to feel dry, then i wait another 12 hours o rmore to put them in curing buckets. even then on occasion i have to pull them back out due to excess moisture. If unsure, just make sure oyu check on them intermittently that first 24 h.. make sure they don't get 'soft' which indicates the too much moisture. They shouldn't stick together too much -- really good weed is sticky, but there's a difference.