Yeah, that works, too. Still I’d prefer to use upvars for referring to any inputs to the (callback function that are supplied by the block - it’s more intuitive for the user, I think. The approach you’re advocating is (IMO) second-best, so I’ll be using that for now - i.e. until anyone invents a way around the upvars issue, or a more local variety of upvars is introduced. Thanks for thinking with me!