I have no idea -- I am quite happy in the US-centric OverDrive ==> Amazon Kindle integration.

Hopefully someone else will be along soon who knows more about these devices.
But first, try using ADE (version 1.7) with WINE.
It is easily installed via winetricks, and runs fairly well.
Hopefully you won't have too much trouble connecting via MTP to the Android offerings.

in fact, I am not at all sure it is as bad as you make it sound. And the non-Android offerings should be fine via USBMS...
You don't
need to pass the USB/MTP connection through WINE to ADE. You can just download the book, authorized via the same Adobe ID as your device, and copy the books manually.