Hope following aids further understanding....
Backup Manager:
Creates and/or restores settings backup. You can setup a receiver how you like it. Flash another Vix image (as a separate prcoess), then restores the settings. Your preferances, bouquets, cam configs, tuner settings will be restoroed to how they were set up.
You can also restore settings between different receivers. For example someone has TM Nano OE and wants a multi tuner receiver and buys a Mutant 2400. Flash the Vix image on the Mutant (as a separate process) and restore the settings backup. Settings for everything that qualifies will be restored. E.g. Tuner A will be the same configuration, but Tuners B, C and D, will not have anything set as nothing was set for them when the settings backup was made on the the Nano which only has a single tuner. The preferances, bouquets, etc will be restored.
Image Manager:
1.You can download an image from download server
2.You can flash/install an image.
3.You can create an image backup. Think of it as cloning the image. This can then be flashed/installed to the same make and model of receiver by USB or by Image Manager itself (process 2 above). When you flash/restore this image, it is an exact clone of the backup made.
Operations 1 and 3 are working for the Solo 4K. So, you can clone the image using Image Manager and restore/flash it using the USB installation process.