Thank you for this additional info 
Usually this system overload message doesn’t appear out of nowhere. My guide (updated for v0.8.2) should be able to help you solve it though: inZOI – Graphics & Performance Guide (revised after update v0.8.2) → Take a look at it and simply adjust one or two of the settings mentioned in there. This should actually take the now completely shifted setup workload off of your system 
EDIT: I don’t own a MacBook, so I’m not totally aware of the inZOI settings available. @lastricerobinson - you should be able to make a few changes from the guide mentioned above and it should be enough too =) Welcome to the inZOI forum btw!