Updating a Service Definition on a non-Hosted Feature Layer (referenced data) via Admin REST

[PhilipWeeks]

I've been trying to update a Service Definition to increase the {"maxRecordCountFactor" : 3} property as I have  large data set I'd like to use a dashboard to filter by year, but even though a single year's worth of data is under the feature limit, because of how the dashboard works it hits the feature draw limit before the filtering and will not display all results.  Even though the definition doesn't appear I've been able to update this property on Hosted Feature Layers but not on a Feature Layer tied to an SDE data source (referenced data).

Does this mean a non-hosted feature layer can't have their service definition altered or is there some other configuration or process I'm missing?  The error I get is a pretty generic:

{
 "error": {
  "code": 500,
  "message": "Error performing update definition operation",
  "details": []
 }
}

and I get it no matter what I try to update.

[LanceKirby2]

I am having a similar issue to this. I need to update the symbology on a referenced feature service via the python api. It works fine a hosted feature service, but I am getting error 404 on the referenced.