Stem snap isnt 100% imo they come in all different sizes . Some just bend some snap but thats just my experience. Learn to feel the bud. crispy outside but still has some rebound when squished. Hard to explain lol
Pull a bud away from the branch it's drying on if it's still bends it's not ready. If you pull a bud and it leaves a stringy bit it's not ready. If you pull a bud and it snaps off its ready for jars.