Up until several years ago, we did not allow any personal devices on our school network for security reasons.
With The change to 5G, we found that there was a lot of personnel that did not have reception in classrooms. We then allow staff mobile phones on our Wi-Fi. This is done through user login credentials and multi-factor authentication.
We've discussed the idea of letting students be on a guest Network. Completely separated from anything on our Network, but found that there hasn't been a huge need at this point.
We can generate 24-hour access codes that we can hand out if needed, and find it for students that need internet access for projects like video recording, etc, that handing out some one-time access codes seems to work well.