Would suggest using the profiles easier to maintain and keep up to date one systems. In my reading of Nudge the post install scripts were for macOS prior to Big Sur, so you would need to use those for older systems.
Also take a look at https://github.com/macadmins/nudge/wiki/Jamf-Pro-Guide#configuration-profile on how to add the config profile options within JAMF for easier deployment.
Hello,
If you use the Nudge Suite Installer you only need the Configuration Profile to set the Configuration of Nudge.
As @caffine247 mentioned please import the Schema for Nudge to make maintaining and editing your ConfigProfil as easy as possible.
If you are not using the Suiteinstaller there will be no LaunchAgent, Logs etc.... the Post-Installscript is then used to create the LaunchAgent and Configure the behaviour of Nudge.
This, in Summary, means if you use the SuiteInstaller and you are pushing a Configuration Profile to your devices there is no reason at all to run the postinstall script since everything you normally would do trough the script will be done with the Suite or trough your Profile.