MUW9DQ: built-in backup is too inefficient(esp space-wasting) & feature-lacking to be chosen in regular cases

[Destiny Architect]

MUW96X: (copy MUVX3W): I witnessed in the present version ms_lts_precise_r8.iso, the only version I've tried it.
MUW9Y9: At least until a good workaround is posted here, I'm marking the severity High as a considerable amount of work is done to create one of these bootable USB drives, indeed several times more since this is multiboot so often several times more installations (so several times more work) plus several times the likelyhood something could go wrong (including also since there is no security (as running any of the installs could mess up the others), so one wants to make backups of this work, possibly regularly. Moreover especially with all this work, one wants to make easy copies of his/her drive for others to use (without having to know how and do all this work again).
MUW993: From 1st trying it now (MUW33Q), "Menus.Resize persistent mode":
MUW9EE: *the backup produced was the size of the media (the target USB drive partition/volume), NOT the efficiency one would expect (the size of the data on that volume, or perhaps a little smaller with compression)
MUW9ES: **In particular, it was .img file, apparently then a raw image file (as say produced by dd)
MUW9FT: **this is often not very acceptable; in my 1st case, only about 35% of the volume was full (recall USB drives are getting bigger & bigger; this is a 32GB; plus one must size up considerably preparing for a multiboot tool as this where it is typically unknown for a while how many distributions will be needed & practically placed on the one device)
MUW9JF: **Less serious, no warning of this bad performance was given.
MUW9JZ: ***and in all cases (efficient or not), good software should point to the documentation of the backup format for both efficiency understanding plus to say use other programs to retrieve (including cherry pick) and possibly create this format.
MUW9MM: I would imagine a simple tar and/or 7zip would do the job, plus offer additional usefulness (as cherry pick and list the filedirs in it), and with (in many cases, as this) with dramatically more efficiency.
MUW9OM: *Why was this not done?
MUW9TN: **Perhaps because bootloaders and possibly formatting would have to be done, as well as restoring the files, in order to properly regenerate the volume? But this software already offers & does these special things to create the volume, so should no problem, yes?
MUW9OV: *What would the instructions be to do it, at least until this is fixed?