I read through the list, there is no way that IPS patches in this context are a violation. None of the original material is used or even referenced in the IPS patches, thus they can not belong ROM files copyright holder. They are collections of assembly code without any of the original material contained within.
The site hosts files in the IPS format which only contain 100% original code and don’t in any circumstances I’m aware of break DRM. These old games are comparatively small and written in assembly language so these are small files that get merged with a text editor that add additional code to otherwise existing ROM files, which may or may not be illegally obtained.
Warning US only: They are often said to be covered under fair use but I am not certain that is true, I would assert they would be fully copyright to the author of the IPS file and whatever license they released their code under. The fact that their code isn’t complete isn’t relevant and it wouldn’t even be considered a commentary or derivative (both types of either fair use or granted license) as none of the original content is present. An example I can think of related to this in market would be “Riff Trax” which are audio tracks released by several comedians who used to perform on Mystery Science Theater 3000. They give a full commentary on a movie but contain none of the original material, it is on you to press play at a specific time during the movie so the commentary track aligns with the film. There are no references I can find in the case law to anything like “rom hacks” for what its worth so I would say this is extremely low risk in my professional opinion, but I do not want to dox myself and present credentials so ymmv.