I think, most of the time a mod use their "mod talk", it's actually to inform someone, or help out with questions. Though I'm sure one or another thing might be added into the chat, or they just want to lighten up the mood.
But if the mods are talking random things constantly into the chat for a longer time. They are using the fuction in the completely different way.
I have witnessed this before, and it's "kind of" wrong if you ask me. If they want to talk random stuff for a longer time into the chat, they might aswell use the regular chat like everyone to be honest.
Not only because everyone will have to read it, but mostly because when using it in a big place like flourite. People go crazy and just spam the chat with random talk just to get contact with the mod. Not that much about getting an answer anymore.
However, there's probably alot of different ways where the line should be for something like this. But I guess there's alot more things to worry about than the mod talk xd.
But as thunder said. If the mods somehow would be able to choose if they'd talk into general, or just local. Still having the red font. Not everyone would need to see the text. Might be useful.
Overall, I personally think the text work very well right now. But I'd understand if it was annoying when having a roleplay. But if the roleplay is getting frequent, and just not some random one threwn together in bonfire. Why not get a custom map for it?
Oh well.