I tried installing Sitecore 9.3 (simple developer machine setup) with the Sitecore Install Assistant. I checked SXA to be installed.
In the config file (
setup.exe.config) all parameters were set correctly and I added one more to install in a physical folder of my choice:
<parameter name="SitePhysicalRoot" value=".....\wwwroot" />
This worked perfectly for Sitecore, but when SXA was installed I got an error:
Cannot validate argument on parameter 'RootDirectoryPath'. Path 'C:\inetpub\wwwroot.....' does not exist
So apparently the SXA installation is looking for the default path?