Vegas Marine, they're right. Besides the fact that the triggers get big, they're really mean as they grow old.
On a side note, I visited my Mom in Vegas (near Henderson) and found this LFS
right by Gibson St and I-215. Are you familiar with that LFS
Let me just tell you, this guy has the best LFS
I have seen. And I've seen a lot of good ones here in Maryland. That is by far the best I've seen.
You might want to ask him (the old guy), he seems very knowledgeable.
Back to the topic, the trigger would probably become irritating to your other specimen once it reaches somewhere in the realm of 2.5 inches or so. And that's not even a quarter of its Max size. Even at 2.5 inches, the 30G is already too small for this dude because it seems to swim a lot.....really swim a lot. It goes back and fourth from left to right on my 4-footer. And my tank is still too small for the guy.
I hope that helps and good luck on your angel. I wish it full recovery.