Discovered this by mistake the other day. I’m probably not the only one to notice it but I haven’t seen it mentioned anywhere else sooo…
The buff that lets you open the chest doesn’t expire while you’re logged out, so you can touch the platform for the buff -> logout -> get the buff on another character -> repeat. If you bring your alts to the platform in advance and can load in fast you can get a ton of chests at once this way. Way more efficient than doing 1-2 chests per hour by running over and opening it immediately. With my connection I can do four at once, and maybe a fifth if I work on my relogging skills a little more.
It also means if you accidentally grab the buff before you’re actually able to open the chest again, you can logout and come back to that character later to open it whenever you want (once it’s renewed itself, anyway).