The last wave is somewhat easy for an end-game Engi, I feel you should work on the AI scripting to make the final wave a lot more dynamic. In fact, all of the boss waves could use this!

Overall I didn't really find it fun as I just sat there with the same drones laid until the last wave where I had to move around a bit and use a different set of drones to kill the two Phoenix. On top of that, 95% of my time was spent waiting for the next wave to show up. It would be great if say, shooting the commentator would just cause the next wave to spawn.

And... there was boss scripting? All I noticed was that a Phoenix would become smaller and regain their shields after reaching 50% but that doesn't seem to change anything else. Most importantly, you've also misspelt every occurrence of trophy as trophey.

Asides from the trophy missions, will there by any other things to provide more of an incentive to do The Crucible? Oh, on that note, the exp reward for the trophies feels pretty poor.

You could have a "Secondary Commentator" (Commentary booths usually have two people inside), that exists as a pillbox/undockable AI base similar to Tartarus, where if a player gets too close, the next wave (usually in Tartarus, all next waves) spawned. A bit of cooldown scripting could stop it from spawning multiple unintended waves. It would be really bad if you had 10 waves dumped on you at once.

There is a small error. When a non-Engineer (I am a seer) enters, it says, "You are not slated to take the challenge of The Crucible, please leave, Engineer." It shouldn't say Engineer to a seer.