I'd love to be able to modify inserters in ghost form (bring up config UI or use the hotkeys), but it doesn't appear to work. Is there anything that can be done about that?

in theory, there's no reason why you shouldn't be able to open the GUI, it's just filtered to Type:Inserter, where a ghost inserter is of Type:Ghost, then you have to do additional checks.

You'd have to ask KiwiHawk if he wants to try and do it or not.

I'll investigate. It sounds like it shouldn't be too difficult 🤔

It's technically possible but isn't simple. Ghosts don't have GUIs by default so would have to fake it. I've logged it for future consideration.

In Factorio 2.0, ghosts will have a UI. I'll wait for that to be released.

This has been implemented :-)