Nice, thanks for your work but i don't think replacing existing HCG with upscaled versions is a good way to go, because of the larger filesize to upload and download, and because it's pretty much useless as every image browsing software already have integrated resampling filters and modern CPU can easily process the pics exactly the same way on thez fly while browsing. Off course having the largest native resolution pics on lossless PNG is still the best choice quality wise.
What @korasen said. If you upscale with any kind of filter then it's technically no longer a lossless rip. You've changed the images in ways that make it difficult or impossible to recover the original data.