missing proxy - how to relink

Hi everybody,
On a purpose, I switched to proxy in the view pop up menu. A few clips appears to be missing (btw this is very strange because I did transcoded all).

Given that you can transcode from the time line (this is crazy!), which is the proper method to find the proxy missing clips in the event and to transcode them? Is it possible to do it in batch?

I'd like to know also if is possible to do the same for clips who are not optimised (Inspector: original green light - optimised red light). I need to know this for an exporting audio process I'm working on.

Thank you so much for you help, from a relatively new FCPX user
Nico