The scripts should run within a minute or two after installing the management profile. We're dependent on the time taken to download the script agent itself but it's not a large binary and installs quite quickly.
You can see what's happening in the log file for the script agent in /Library/Logs/Microsoft/Intune. It shows in the console app under Log Reports as IntuneMDMDaemon YYY-MM-MM--HH-MM-SS-xxx.log.
I talked a little about filtering this log file in this blog : Deploying macOS apps with the Intune scripting agent - Microsoft Tech Community
My expectation is that you'll see the log file get created within 60s of enrolling (that means the script agent is running) and then you should see it check in to the gateway service and start to process work immediately after that.