I don't know the technical explanation of what is happening behind the scenes, but I do know that oftentimes, when I'm having copy and paste issues (like the extra line breaks you describe), if I use a different PDF reader (specificallyApple Preview), the text copies properly, without the extra spaces and lines breaks.
There must be something that happens under the hood when you Edit the PDF, that tells Acrobat to remove all the extraneous line breaks. Aple Preview does that automatically.
Maybe there is an alternative PDF reader that you can use for this purpose. I honestly think that may be easier than trying to have the vendors prepare the PDFs differently.
... View more