I was able to get the external PowerShell custom action to work; I just had to add it to the Wizard Dialogs Stage instead of the Install Execution Stage.
as an alternative, I tried using the Windows PowerShell Script from file custom action to set the property values instead of an ini file, but the values are not getting to installers.
I created a Feature-based exe installer with many MSI packages. I'm able to pass static property values (/qn APPDIR="[MAIN_APPDIR]\Integration" EFORMS_ENABLED="[EFORMS_ON]"), MSI Property=EFORMS_ENABLED Bootstrapped Property=EFORMS_ON but I have some properties that will be diffe...