I think you can get LVTs up to 20x24 from Chicago Albumen. IIRC top res could only be had to 4x5 or so, though, and that was in excess of 3000-4000 ppi, permitting 10x enlargement. At the larger sizes I think you are getting a ~508 ppi neg, IIRC.

And yes, you can do any evil manipulation you want to the file that gets fed to the LVT! E.g. scratch and dust removal....