I wonder how smart this system is going to be — it’d be wise to have the rewards & purchasing happen on a stablecoin to avoid this. Then make users have to choose to then stash it somewhere they won’t draw from and trigger these events, if they want to “invest in a crypto”. It’d also be wise because coinbase can then charge their fees as they so do.

This is also fundamentally not so different from e.g. having spend vehicles with your brokerage. But the addressable market may be higher / different for coinbase which could cause a lot of headaches, like this one, if not carefully managed.