@silverpill any idea if there's a FEP regarding how to sign an activity that gets propagated through the Forwarding from Inbox mechanism? https://www.w3.org/TR/activitypub/#inbox-forwarding
My first instinct is to use the instance actor for the server that received it, but I'm not sure.
Maybe the actor that received it in their inbox would be better, but that feels slightly unsanitary.