@Michael T Thanks for posting in our Q&A.
For remote team viewer, it doesn't support organization-owned devices. So, it is not supported Android Enterprise fully managed devices, Android Enterprise dedicated devices and Android Enterprise corporate-owned with a work profile devices.
https://learn.microsoft.com/en-us/mem/intune/remote-actions/teamviewer-support
For custom notifications, could you please share which article describes it doesn't support Android Enterprise fully managed devices? Based on my understanding, intune custom notifications aren't supported by macOS and Windows devices.
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