Hiding Curve Editors (Retime Editor) for multiple clips -

you wanna Retime one clip and open Curve Editor for that. Then go to another clip in the Timeline and tweak another clip's Curve Editor. So at the end you are ending up with the bunch of opened Curve editors on the Timeline here and there. To close (hide) them you need to select clips with open Curve Editor one by one. What if you have like 50 clips with Retime?

How to close (hide) Curve Editors (Retime Editor) for multiple clips at once?

i believe, you can't. they need to make it like with Retime controls, where you can select everything and press the shortcut for Retime controls twice, so it will first open Retime controls for every selected clip, and then close it for every selected clip.
for some reason, you can't do that with Curve editor...

Best idea might be to close them down as you go.

Hi! Hopefully, it will be useful. Try Shift+'C' or find in the keyboard customization "Show curve editor"