Hello,
Yeah, the "Center (contain)" should be default for custom images, I will fix this in the upcoming release.

Also, you say import in Chrome failed? That's sounds impossible, it's build from the same source code, it must work :). I will investigate now. And you are right, after the import it will look exactly the same.

If you have a lot of dials and thumbnails, the import may take a while depending on your drive speed (slow SSD can take a whole minute or more to import 40MB backup file).
Could you please write me to my support email what was the size of the exported file? And was there some error written? And did the dials at least partially imported?
Thanks!

Best regards,
Juraj Mäsiar