I’ve just discovered OpenAudible too.
I thinks its a great application and well worth the small cost as it takes away all the hassle of how to download your audible library and easily convert to a suitable format.
It gets some hate from people disliking that it’s paid, but the ‘free’ alternatives only handle the conversion and not
the download.
n.b, to note a bug has crept into the PMS affecting it’s ability to accurately parse and stream m4b files to Prologue/Chonicle/Bookcamp, but a fix is on the way…