Is it possible to make hyper backup task which will backup iSCSI LUN to encrypted folder?

It appears that it is possible to backup folder (encrypted or not) to unencrypted folder.
It also appers that it is possible to backup LUN to unencrypted folder.

And, it also appears that it is possible to create backup task which will backup iSCSI LUN to unencrypted folder AND then after the task is created you can change encryption setting of destination folder (and continue with backup).

Is there a reason why is that so, or is that simply a programming issue?