Is there any way of disabling $content and $type fields from generating when I am serialising generic object

[rotolonico]

Let's say I am, for some reason, serializsing the simple "test" string but casting it into a generic object.

Fullserialiser returns me:
{"$content":"test","$type":"System.String"}

Is there any way to tell the serialiser to only return the $content value?

This question was asked before here but the solution of using DoNotEmitTypeMetadata attribute no longer seems to be working