Why don’t you store your live Manager data files to Dropbox, so when you start each PC and the files become in sync, then you can just open Manager and go without needing to “import backup”. This doesn’t change the need to keep separate backups.
To do this you need to change your Data Path under About Manager - but read this topic first - as you need to leave the “data” and “size” files in the original location appdata-manager folder.
However, if you wish to continue using your current process, then .Manager or .zip doesn’t change anything - just import backup as per normal - you don’t need to unzip first. BUT all PC’s must be kept on the same Edition of Manager as data files are not backwards compatible.