Thanks for the patch, I think the overall idea is sound.
However, does it really make sense to test for configuredProfile in this line? I'm thinking that when p-p-d is uninstalled, the behavior should be the same regardless of whether or not the user had previously configured a profile when it was installed?
What would be going wrong if we simplified the expression to the following?
readonly property bool isInDefaultPowerProfile: !activeProfile || activeProfile === defaultPowerProfile