uBlock Can Block MutationEvent :)

Just include the following rules:

##script:contains(DOMAttrModified)
##script:contains(DOMAttributeNameChanged)
##script:contains(DOMCharacterDataModified)
##script:contains(DOMElementNameChanged)
##script:contains(DOMNodeInserted)
##script:contains(DOMNodeInsertedIntoDocument)
##script:contains(DOMNodeRemoved)
##script:contains(DOMNodeRemovedFromDocument)
##script:contains(DOMSubtreeModified)

developer.mozilla.org/en-US/docs/Web/API/MutationEvent

Note that unless author has specifically isolated Mutation-related logic to specific block,
more functionality would be lost (wellllll…. daa…!!!!)