Hello @nitbit!
Message: dfu-programmer: no device present. is stating that programmer cannot see the device, but it does not mean necessarily it is not available or connected.
I think this might be an issue caused by not using terminal with Administrator privileges (I do not see mentioned anywhere in your description). If you are using Windows 8 and up (perhaps Windows 7 too) please click the Start button with right mouse button (RMB) and choose Command Prompt (Admin) and retry the procedure. Command prompt should be as well available from start menu somewhere.
Device in Update mode is not communicating at all with the Smartcard inside (for which it needs the firmware), hence this cannot work.
If you wish to get back to current firmware installed on Storage device, the programmer’s launch command you have mentioned should clear the Update mode and start the device.
Firmware data should not be overwritten just by changing the mode. And it seems from pasted log, that the firmware update strictly has not started at all, so everything should work!
Please let me know if that has helped. I am glad you like using it!
By the way, App v1.2 is not supporting command protocol changes introduced in Storage’s firmware v0.49. Please update to v0.50, which has reverted this.