This was determined to be “built-in” expected behavior on all operational layers as of the new release of Collector for ArcGIS 18.1.0 iOS and the workaround that we have implemented is to add (move) one of our pictometry or reference layers into the base map group. Then when collecting features in Collector, that new basemap layer is the reference and therefore no longer blurry. Not an ideal solution but it works. Our case was initially logged as a bug then an enhancement request since the behavior was, as mentioned, “built-in”.