FWIW, my time to restart remains pretty close to 30 seconds.....in my update process I HAD to download the disk image updater from Apple Support and apply the update using that since my normal process from Software Update got corrupted during the install process and wouldn't pass the last step of verification.
Maybe re-applying the update using the
stand-alone updater will resolve your issue.
Perhaps you lost some of your caches and are still rebuilding since your manipulation using non-standard cleaning?
Not sure if the newest OS truly benefits from as much manual intervention as past OS's........it is quite a bit different under the hood.
edited to correct update terminology from "combo" to "stand-alone"....
