May I request you keep the old one up as an archive whilst the new ones are uploaded seperately?
Whilst I know your HD rework will be far superior to the old ones, some of us do like the 512x512 original quality aesthetic.
I might be completely lost with what you are proposing here, but as a modder who uses your modders resources the way you setup your previous upscale mod was very convenient for me.
When the mod is setup like this above, these three files are all part of the same download page but I can choose to download one or the other.
If I was a player with a low-end PC and slow internet I wouldn't want to download the 4K TGA version due to the file size and so I'd stick with the 2K TPC version instead.
This method best caters to everyone's needs, whether it be a low-end player, a player who wants to play with HD textures, and a modder who wants to access the raw TGA files.
The only thing one could complain about is how there isn't a 2K TGA version for modders who want to view the lower resolution option.
Of course, I might be missing the point of your thread completely - if I am please let me know!