Auto-update would be convenient indeed. That said, Developer Edition is really very stable, so while I see why you would not want that, it's not that bad a stop-gap measure until unbranded builds auto-update.
It's perplexing that Mozilla insists on forcing signature checks at any cost in release builds, when there is no consensus on the fundamental reason for doing so.
> Most fundamentally, the full Firefox team does not have a common understanding of the role, function, and operation of cryptographic signatures for Firefox add-ons. For instance, although there are several good reasons for signing add-ons (monitoring add-ons not hosted on AMO, blocklisting malicious add-ons, providing cryptographic assurance by chaining add-ons to the Mozilla root), there is no shared consensus on the fundamental rationale for doing so.
