According to my testing with inno setup packer which I believe is used to create the Pitool install files,
It seems possible/easy to add support for custom install locations during installation.
When creating a new script for generating the install files, you can toggle whether you allow user to select a location.
Also to note, the install by default finds and uses a previous installation to detirmine the path, so if you do some reg changes to make it think it’s installed somewhere else it basically achieves the same thing, just in a hacky way.