I hadn't even heard of Parallaxgen before today - I've not played Skyrim in a while! I will try and read up on exactly how it all works but @JustThatKing (who is on annual leave) has kindly given me a little more context on this issue.
If this is the case you'd need permission from the original creators of the assets to distribute this content, as is the standard for any modification to mod content created by other users. The onus would be on the mod list curator to obtain that permission. Alternatively, they can provide instructions for the user to run the required tool at the end of the process to generate the required files themselves. It doesn't look like it does something so fundamental the game would be broken without it.
As far as sharing it if you do have the required permission. Collections have always allowed you to ship "Bundled mods" with them and this is a perfect use case for using that. Similarly, we allow binary patches to be shipped which may be a way to include the tweaks to the models without distributing the entire file. It also prevents the spam of mod pages that contain content which is entirely non-functional without a specific mod list installed. If you're not using Collections or need to use a mod page for some reason, there should only really be a single mod page per mod list and it contains all the supplementary files - unless there's a compelling reason to split it up.
Happy to discuss further, but I'm going to be AFK for the holidays shortly so I don't currently have the time to dive into the nitty gritty myself.