A big part of Devcon are without a doubt the off-conference events. Last year there were several websites collecting those, the biggest one probably being https://www.offdevcon.com/.
I feel like this could be a bit more supported by the official conference. Maybe with two tiers:
1: Official off-devcon events
2: Open list
For the official ones event hosts have to register and apply in advance. This could then also be managed to avoid having too many high-quality events at the same time and day.
But either way, even without tiers just having one list with all events would be quite helpful.