Alright. So I figured out that error. Needed to go through the notarization process with Apple Developer. Now it no longer says it's damaged. It does throw a tantrum on the file being downloaded from itch, but it works when you tell MacOS to run anyway.
I would try the webGL version, but I am using some shaders that require Forward+, which isn't compatible with a web release, from what I understand?
Thanks again for your patience!