A lot of communication between people is non-verbal. Also, the interaction with drawing software is not the natural way for people to convey their ideas, we tend to use our fingers to point, to draw etc. For some types of problems, I stand by my point, that first person interaction speeds up problem solving. But obviously there are many kinds of problems that do not benefit from this. So the way we usually structure this, is we set a date/time when X people from a team work together in the same room, if it makes sense to grind through things together. And at other times, people choose their own schedules / workplaces.