Hello, I'm trying to use the page builder to upload a webp image - which would be higher quality and smaller in size than a jpeg. This used to be possible but now isn't allowed! Is there a way I can change this?

Which version are you using? As long as your server supports the webp format it should show, however there was a bug in 4.7.0 preventing it from showing in the list. The issue is fixed in version 4.7.1.

Thanks, that did it. Was on 4.7.0 originally.