Machina - Data Compilation
Here's all of the data I have managed to catalog regarding Machina portals thus far. If you have anything to add to this, please let me know! I'm working to make this as in-depth as possible.
My current biggest unknowns are whether portals will continue to link past level 8, and why certain portals choose to not link when they are able to. Any theories supported by data that can be further tested are absolutely encouraged and welcome! The more we know about our new foe, the more we can keep it under control ;)