[cybmole]

i was not serious about auto-purge just making a point.
so why convert from latest version ( which you call intermediate) - well -

to spell it out one more time. After using epub for years I bought a new Kindle Fire HDX & I wanted to see how my epubs would look on that, in the native app , in AZW.
not my "as published" epubs but the " painstakingly tweaked to use my preferred fonts, margins etc" versions that I'd created. but I am NOT ALLOWED to do that , unless I first remove all the original_epubs.
That is not version control, it is not something i need support for, it is IMHO a reasonable request for a genuine scenario
but hey ho, the Wizard of OZ disagrees, strongly.

PS, before all of this I'd spent a long time re-adding books & ensuring that I had original_Epubs, after previous rash bulk conversions had left me with tweaked versions that were no longer ideal . they had been done for epub device A, but I'd switched to epub device B & wanted to start over.
so I have strong reasons for not wanting to remove them.