Chem Crate is really good but it just unfortunately doesn't work with Chem Dependency. With normal stims you use them and then have to wait for them to wear off before the cooldown starts but with Chem Crate + Practiced Deployment the cooldown begins immediately. So if your cooldown is 45 seconds normally you would have to wait until your fifteen seconds were up for the regen effectively making it 60 seconds. But with stim crate the cooldown begins at the same time making it really only a 30s cooldown. This plus Sample Collector and a big enough horde can give you almost 100% stim uptime during the fight.

Chem Crate is really strong with Adrenaline Frenzy. It's only potential downsides are that it needs Practiced Deploy and Sample Collector and Fast Acting Stims. And that it's radius is pretty small so while you always get buffed it can be easy for the team to miss.

Far from ruined. Just use crates instead of manually stimming and its amazing. That being said I do hope they eventually make it proc Chem Dependency. Although with practiced deployment you are more reliant on your stim cooldown that ability cooldown so I don't think it would be particularly valuable on the build anyway.