Just discovered your remastered games after watching a let's play of Legacy Realm of Terror and looking up whether there were other games by the same dev. I like IF classics like Zork so this might be up my alley.
However I must point out that the upscaled images you described here look terrible, you can just see the algorithm, ugh! I tried using this kind of filter in emulators and quickly went back to the original graphics. It's like pixel graphics leave the details to the imagination, while the upscaled ones just show you ugly details. I much prefer the originals.
Hope you make available the original graphics with a pixel-perfect upscale version, i.e. one pixel becomes four pixels of the same color at higher resolution, pretty much what the Integer Scaler free program does.
Perhaps AI repainting might provide better results these days, as stuff like Stable Diffusion is able to work from a base image and a prompt including a description and style, and pretty much produce a new painting that's very close to the original but doesn't look like a cheap upscale. Just don't ask it to draw accurate hands or axes.
Edit: I had missed this at the bottom of the blog post "all these enhancements are done in realtime on your device (we're not changing the images actually stored)" - definitely breathing a sigh of relief here. I think it needs to be a big disclaimer in bold at the top.