Zorin 16 Pro to zorin Pro 17 update

I am in the process of updating Zorin 16 Pro to zorin Pro 17 using the Update App as advertised yesterday by Zorin. The app checked the laptop and found the Public key for Wine was missing. I fixed that and the update continued to the Upgrading screen.
I have a tick on "Preparing to upgrade" and a twirly circle on "Installing new applications". It has been at this stage for over 2 hours now.
My questions are (1) How long should a typical installation take (assuming I have a 5 year-old laptop with a SSD, 16 Gb ram, and 50 Mbit Internet speed)?
(2) How do I test the upgrading process to see if it has hung without interfering with the upgrade if it is still going OK?
(3) Can the update be restarted if it has hung?
(4) If hung, can I still boot up into 16 Pro?
I can let the app run all day, but if it has hung (infinite loop) this will be pointless. Please advise. Thanks.

In testing the Ubuntu Direct Upgrade, I had it take three to four hours. In fact, it was one of the primary reasons I have been unenthusiastic about ZorinGroup introducing a direct upgrade option.

However, Zorins version does seem to operate a bit faster. Some users have noticed slow network speeds due to the recent release of Zorin OS 17 and the upgrader as a large number of users rush to use it.
So, I wouldn't give it longer than four hours.

Can it be stopped:
This depends on whether it is merely in the checking stage or if it has begun to overwrite packages. If overwriting is occurring, it cannot be stopped.

I decided to use the System Monitor App to see if there was any disk activity with the Zorin Update App. There wasn't so I saved all the settings and serial numbers for apps I would need for a clean install. I rebooted the laptop with the original Zorin 16 Pro, twice, to make sure it was booting to a stable start. Then I ran the Zorin Update App again and it worked perfectly. The installation of 17 Pro took only about 30 minutes with no holdups or problems.

Here are a few suggestions:
(1) as instructed, run the system update app on 16 Pro before doing the main update to 17 Pro.
(2) reboot your computer at least once before starting the main update to 17 Pro.
(3) watch that the blue progress bar at the bottom of the update window actually moves across the screen. It is slow, but if it hasn't moved at all after a few minutes then the app may have stopped.
(4) keep the .iso file handy in case you need to do a fresh install. Since the .iso file is bigger than 4 Mb you will need to use Ventoy to make a bootable USB.

I like the look and feel of the new version. I might need to make a few tweaks here and there, but overall, the conversion from Pro 16 to Pro 17 was successful.