You could make a new upgrade and give it to all players when player 1 writes "-noair"
Then on all the units you can make them have a requirement under show which is basically: not(Count upgrade(*Your custom upgrade* completed or better))
If you did this, you would only have to add the new upgrade for all players instead of disallowing all things. However, this is a bit more complicated solution and I take it you're not that experienced with the editor.
For you, the best solution would be to do it through picked players. I don't know why it didn't work for you. Can you show us the trigger where you used picked player? Remember that you have to have it in a "Player group - pick every player" loop
Also, I don't have the editor in front of me so some actions and stuff might be named slightly differently.
For the message, I usually use debug messages. Although, I think there's an action in the UI category.
Another issue I'm learning is that a lot of the air quality sensors don't work at very high ambient temperatures. I'm planning on heating this enclosure to like 60C or so, and that's the upper limit of their functionality
Although I don't know if I need to actually actively heat it or just let the plate and hotend bring the ambient temp to whatever it will, but even then I need to figure out an exfiltration for hot air. I think I kind of know what to do but it's still fucking confusing
I don't think I'm dealing with quite the same pressures though, at the very least its a significantly smaller system. For the time being I'm just going to put together a quick scrubby box though and hope it works good enough to not make my house toxic
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.