If system messages like 'that item cannot be jettisoned' cannot be suppressed, can they be put on their own channel so that we can suppress them by leaving said channel?

Humm. The problem becomes the support overhead of newbies leaving the channel and then complaining they didn't know.. X, Y, or Z thing.. like, I dunno, warnings about shooting in a NFZ?

We get a ton of "I didn't realize I would (X), please give me back my (Y)" support tickets already, I can imagine that getting worse.

Maybe if it required a certain level (which is kinda complicated to implement), or had some server-side toggle to flip where you un-subscribed from local messages. I dunno.

For a lot of the messages, it's not a big deal, but when you are doing something like mining with a plugin that jettisons, those messages really spam the chat window.

I can see where it would create more headaches for you which is something I'd rather avoid. This is a 'would be nice to have' because the spam really disrupts having a conversation while doing certain activities.

Edit: Would it be possible just to suppress them so that they don't print to the players screen more than x amount of time since the last time?

This sort of thing is best implemented by a plug-in because every player probably has their own opinion on which messages they'd like to see and which ones they'd rather not, and using a plug-in gives you the freedom to exactly tailor the behavior to match your personal preferences.

Checkout my HUD Messages plugin, which could easily be adapted to do what you want. It suppresses certain notifications in chat and displays them temporarily on the HUD instead. With a little tinkering, it could be made to simply suppress the messages altogether. Plus, you can hide just the specific messages you find annoying and keep the rest.

I don't think the 'item cannot be jettisoned' message is one of the ones it currently intercepts, so some modifications will be necessary on your part. While you're at it, you could add in some fancier features, such as show the first instance of a message but suppress the subsequent ones until the player changes sectors or something.

Awesome! Thanks meridian. I'll take a look at it.

Yeah printing system messages to the hud instead of chat would fix the problem for everyone.
In case any coders are interested - The lua code for it is....

if HUD.visible then HUD:PrintSecondaryMsg(Text)
else
print(Text)
end