Hi, @Devin Arthur
Thank you for posting in Microsoft Q&A forum.
It is not possible to add ARM64 support in MDT (Microsoft Deployment Toolkit) as it only has the option for x86/x64 image creation. There are no workarounds, nor are there any plans mentioned to add ARM64 support in the future.
https://learn.microsoft.com/en-us/mem/configmgr/mdt/release-notes#supported-platforms
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