Currently in Map Viewer and application built on top of maps there is a limitation to only show up to 8 decimals of precision. NOAA's National Geodetic Survey currently has an feature layer, web map, application that requires us to show up to 10 decimals of precision to properly display the parameters for the current Alpha State Plane Coordinate System of 2022 Experience. While 8 decimals is enough for most of the zones it does not have enough precision for all zones.
I am posting this from my personal account since my organization login is having issues with Esri Community.
Thanks
Brian