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I envisioned space at the other end of the Expo hall with a few large round tables with power and either reliable wifi or wired connections. Maybe access to loaner computers and hardware like Arduinos, so things can be set up ahead of time.
The adult-friendly activities should be fun or valuable enough to lure people into the expo hall, but not require such a time commitment that they'd need to make a choice about whether to attend a talk. The key would be that the activities are something people could just stop by, participate, and leave.