@Firstly, apologies for the delay in responding here and any inconvenience this issue may have caused.
No, JSON is not supported on any of the spots you mention.
If you are looking for this feature, I would recommened you to leave your feedback here. All the feedback you share in these forums will be monitored and reviewed by the Microsoft engineering teams responsible for building Azure.
Hope this helps!
Kindly let us know if the above helps or you need further assistance on this issue.
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