I use GoToAssist. I share screens with new people and new PCs everyday. The reason I like it is it takes less than 90 seconds to dial a random person, have them visit a website, type their name and a code, download and run the client, and connect to their screen.
Via group policy - https://support.logmeininc.com/gotoassist-remote-support/help/set-up-unattended-access-g2ars030001
GoToAssist might work for you if you have access to tech soup. I believe they charge technician/month instead of per device.
You could probably roll a DIY from a VNC derivative, but if you are willing to pay for broad support and a working solution, maybe try:
I know they have preconfigured installers and license by the tech (or at least they did a while back).
Yep! I don’t have any experience with other service desks to compare but I like it. https://get.gotoassist.com/service-desk?c_name=gget-d-c&c_mark=NAPPC&c_kwd=service_desk-SITELINK&gclid=Cj0KCQjwre_XBRDVARIsAPf7zZglm4JJCKJM9NOndOybX72ZGY_b-EdTFVv9muOsy4xvRpyTPMmR8lEaAtwEEALw_wcB&gclid=CJrPsd3gi9sCFduVxQIdDSsNOw&am...
If you are trying to support a naive customer, and you are using TeamViewer, then you're doing it wrong. There are much easier applications (from the customer's perspective), where it's a simple as clicking a link. GoToAssist is pretty much foolproof. They click a link, click OK to install, and enter a number for you to connect. TeamViewer is IMHO way too much effort.