My take: "My god, we need another channel?"

Personally, i think it needs to simply be labled "OOC/Banter Chat" or simply and dumbly put "OOC Chat".
I simply think that the reason why we have this problem is because "Banter" is too wide a term. And new to new-ish players assume Banter means "Bullshit my character says", rather than "What RL me says"

Though, it appears you cover that when we type in Banter. So this may also be a problem that doesn't exist.

And also, i thought "IC Bullshit" was what Common Grounds was for... No? Hmm... this idea could solve that problem. The "make it more obvious" idea worked with the Factory... or whatever Down Below was called.

Common Grounds is actively used as a real location and place on the Island. It's a place that has a history, a built background, and a story line. It's as much a part of Island life as Sheila's, eBoy's, or any outpost.

What's being proposed here is a "non-serious, non-canon pseudo-RP" channel. A place where people can be goofy and silly as they want and not have it actually influence or be thought of as anything that their character is actually doing in their storyline and have no effect on their ongoing narrative.