As of now there's not a plan to add a feature to manually edit the device history list. Over time devices will fall off on their own, but there's no way to manually edit the list. We have passed along the feedback to our internal teams that it's a feature that users have requested. If there's anything else I can do for you, please let me know.
I wish I would have just bought a router and installed DD-WRT on it instead of buying this pile.
I cant believe that it would be so difficult to add this feature. i have dozens of devices that do not come off the list. See video link above.
We hear you and we appreciate you sharing your thoughts about this. We're not quite there yet, but we're always looking for ways to improve and again we'll take this as feedback.