Thanks for starting this conversation, Comtesse. I'll pass on a notice to the QH Co-op group so that individuals may comment.
Speaking for the group as a whole, we don't have regular times where we congregate. There's usually a few of us online at any given time of the day (though our avatars may be napping while the typist is pursuing RL activities).
You could always ask at the G&S Market Forum if you are looking for something specific or check out our inworld Market
Would you please post a SLurl for the Magritte Market?