I have Deadlock and am able to invite people, if someone wants an invite just comment with your Steam URL (or DM me) and I will send invites out later today to you.
Similarly, if there are others out there who want to share invites please feel free to comment your Steam URL (or whatever).
GLHF!
PS, if I've added you as a friend but you've not heard from me please feel free to message me on Steam or leave a comment on my profile and I'll invite you ASAP.
Ah, bummer, I have no idea. I've got the option to invite friends from the main menu and am trying to help others play that were interested.
If such a restriction is in place then people will have to wait.
I'm still happy to invite. Thanks for the heads up.