@Aran Billen, Thanks for posting in Q&A.
From your description, I know you want to block add-ons within edge via Intune but failed.
Based on my researching, currently, Microsoft Edge is not available for the feature, so you cannot achieve your goal via Intune.
Therefore, it is recommended that you submit your feedback to Edge. When this feature is implemented in Edge, only in the future will Intune have the relevant policies to manage Edge related features.
Thanks for your kind understanding.
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