First off there should be an option to turn off saving messages to a back up.
If Apple allowed finer tuning of a backup then you could weed out bugs that transfer with them.
Point in case this bug. It's annoying how "great" Apples backup method is until you have a problem. Then the first thing everyone says is "restore from new!".
Now I'm watching how the space is taken up with each message. Restoring doesn't sound like the best option given that we have to redo all the settings again (reduced motion, auto update, contrast..) which are spread all over and takes a good amount of time.
Is there a way to save the current settings, restore as new and then have all those settings?