Yes - it is possible but as already covered above - don't yank a mounted drive.
Under Hyper Backup task settings there is an option on the lines of "Remove destination external device when backup task has successfully finished". That way when you know there is no scheduled task running you can just pull the USB drive as it will not be mounted.
Most tend to leave drives connected though and just have different scheduled HB tasks going to different drives; that way you get a rotation with no cable pulling required. It isn't perfect though - I like an air gap and ideally a longer schedule rotation than offered by HB. I can do the first via a network drive on a power schedule but HB settings are what they are.
A simple, more secure practice is to leave the USB connected, and run the alternate backup to a cloud provider. In that way, should fire, flood, theft, malware... befall you. you have a safe "go to" backup.
I think most are knowledgeable about what the cloud offers vs additional drives but the cost can be prohibitive if you have a lot of data or even just terrible internet bandwidth. An off-premises & rotated USB drive can be the limit for some users. They are way ahead of those who have zero NAS backups!
Thanks for all the advices.
Our main worry is really ransomware... and as you know it can "reach out" to the cloud too...
Will manually unmount the disk - no big deal. Just that it needs a - relatively - more competent user to do it.
Thanks - having experimented with this I can pretty much confirm that HyperBackup will not accept a new disk, even if formatted identically, having same capacity and same file structure, for the same job.
So in effect one has to create as many jobs as disks