We ship a PowerShell script with our application, and we also want to run the script at install time. We want the script to execute from [APPDIR].
Using a PowerShell script custom action, we can achieve this; but the installer behaviour is to create a temporary file containing the script contents, write it to disk, execute it, and then delete the temporary file. This was causing a false positive with certain anti-virus software and breaking trust in some customer environments.
There's no custom action that lets me just "execute this PowerShell script from the place it's installed"
As a workaround, I wrapped the PowerShell in a .bat and invoke that using the "Launch File" action.