Import XsltListViewWebPart definition
It is actually possible to import the definition of a XsltListViewWebPart via LimitedWebPartManager in CSOM. However, not all properties are supported. Important properties like XmlDefinition, Toolbar, ViewStyle, .. are being ignored. There's no possibility to have everything set correctly not even manipulating the backed view after importing the WebPart. Please read also this discussion:
Thanks for your feedback! Although we appreciate your time and effort to give us this feedback, it’s not something we’re planning to do right now as we keep on prioritizing our resources and investments on the modern capabilities.