I think it's either possibly a permissions issue with some of the necessary admin files (the new location is in "Inetpub", not "Documents/Git" or a Macro signing issue. When I switch the local IIS site location back to the working location (both the working and non-working locations are running the same database), I can see Event Log entries with the following errors:
There are about 20 or so of these after the APPLICATION_START event that are all similar failed security checks. I tried going through the re-signing process detailed in the documentation to no avail.
Even weirder, I cloned the GIT repo to another PC entirely and it works over there. Only when cloning the repo to the same computer in a different location does it do this...really weird.