Some more low-hanging fruit admittedly. Complementing the Original Main Menu Backgrounds for Remastered Mode mod, here's basically the same deal but for all three game's loading screens. They've been resized up to 1440p by sharp-pixel perfect Nearest Neighbour scaling and then downscaled from there to the game's required 1920x1080 via Lanczos scaling, retaining most of the sharpness (but not all). 

Like Unlike the main menu mod, I did not yet double-check all the various versions of these games to find the best quality versions loading screens or what have you - these are very much the same as the ones that ship with the remaster's Classic Mode.

Installation Instructions:

• Navigate to the game's folder. In Steam, this can be done via Right Click -> Manage -> Browse Local Files.
• Optional step: in each of the 1, 2 and 3 folders, create a backup of the PIX \ HD folders. Otherwise you'll have to Verify Local Files in Steam to uninstall this mod.
• Download this mod.
• Open up the file you just downloaded with either Windows Explorer, or 7Zip, or WinRAR etc.
• Drag (or otherwise copy/extract) the folders '1', '2' and '3' out of the mod archive and into the game folder you opened. Replace when prompted. If you don't get prompted, you extracted the files to the wrong place.