[Desperately seeking Lightroom replacement]

Same here. Been using an ancient Lightroom 5.7 for organizing for years, hating every aspect of it. Imho LR is user-unfriendly as hell, nothing is where I expect it to be (regarding the library - development is quite okay though!) - so many times have I messed up the image tags, because I mistook that menu for the well-hidden search... 

AP already has a well-working development persona, there would just need to be a library function with preview-generation, tagging, search, camera import, (batch) export and direct access to the development tab. Then a button to continue editing in AP - voila!
I am sure for lens corrections there is a supplier that sells pre-made databases. Such things as face-recognition or auto-development are not really necessary imho.

Anyway, if Serif decided to build something like this, I am sure there would be plenty of happy takers