I found a workaround for this that is similar to other workarounds for enums where you store the data in a private property and have a computed property that gets and sets it using the type you really wanted to use. My stored property is a string and my computed property encodes and decodes to and from json. I assume this is essentially what SwiftData itself will do when they finally add support for enums with associated values.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags: