My group does not use the video chat nor voice chat options in Roll20 at all, yet every time I open a campaign, I and my players all have to switch Video + Voice settings to Disable.
This is a frequent annoyance for my players who have to wait for OpenTok to load scripts into their browser when none of us are going to use them. If I, as the GM, had the option to set this at the campaign level and have it persist from session to session, it would save my players a lot of hassle.