Hi Antonio. I have purchased Affinity Photo and am quite pleased with many of the features of it.
As for Lightroom being able to read files - - - Affinity does have it's own proprietary format called .afphoto. When I attempted to Import those files into Lightroom, they were NOT recognized.
However - files from within Affinity Photo can be Exported out using popular formats like JPEG, TIFF, PSD etc. All of these formats Imported into Lightroom without issue.
For my workflow though, I am always Importing my files from my memory card into Lightroom as a first step and way to keep my files organized. I who never find myself opening any files in a Photoshop or Photo style editor as a first option.
And so there are no file compatibility issues with Affinity Photo if done this way, as I would open any files required more extensive composite work, from within Lightroom and when done, Affinity Photo sends them back to Lightroom where I can continue on processing, saving and printing.
I have just put together a video showing the steps involved in setting up Affinity Photo as an External Editor for integration into Lightroom Workflow:
---------