I'm sorry for leaving it in a relatively uncertain state so long, but I'm officially archiving it now until I can find the time to make & maintain an actually good solution.
Procrastination is a bad thing - Me, after not working on features I should be working on and instead making an entirely new project.
Immersive Portals and Create don't play well together.
"Vanilla" Create is unable to link tracks across Immersive Portals,
and the rendering of contraptions across portals is buggy.
This project is an attempt to alleviate some of these concerns.
To those that like their mods finely polished and entirely without bugs from the outset,
I recommend waiting for an official solution, because this was written within as little time as humanly possible, and thus is liable to break.