This heatsink from Khadas is well designed to match their VIM3 (and presumably the Edge). It comes with two thermal pads (one for each model) that can be trimmed to provide adequate coverage for the SOC, RAM, and PMIC. I need a bigger one or one with a fan to avoid throttling and core shutdown. This one is probably perfect for things like TV box/media center use where CPU usage isn't high and silence is preferable to over-the-top performance.