This is quite nice, I'm going to use it on some alts.
I'm a little hesitant to make the following request since I looked at the code it's simple and does exactly what it says, you probably wouldn't want to complicate it.
Anyway, I've found that I prefer the mail client's approach to unwanted messages, which is redirect instead of discard.
Would you consider adding an option (even if it is set in lua) to redirect the filtered messages for the session to another chat tab?
What I mean is something along the lines of "look if the user has a chattab named 'Spam' or whatever they have set and print filtered messages there".
Accept or decline, thanks for the addon goes without saying