ArcGIS Pro has certain default transformations that it applies to new maps. Organizations may have their own standard transformations that should be used for certain geographies and certain geographic coordinate system combinations. The ability to override the ESRI defined default transformations should be in the options so that GIS users within these organizations do not have to re-set every map from the sometimes long and confusing list of assumed to be correct transformations for the data in the map.
There was an Idea for ArcMap which contains good comments here: Ability to set another default datum transformatio... - Esri Community
In the post above
it would be nice to also have the option to establish default transformations to use with the default spatial reference.
For example, if the default spatial reference for new maps is set to some zone of the SPCS using NAD 83, then to also have the option to set the default transformation to be used if WGS84 data is added to the map, and the default to be used if NAD 27 data is added to the map, etc...
For many offices, most of the data added to their maps typically use the same two or three different datums, so having the option to set default transformations for these datums to their map's default spatial reference would alleviate the bulk of transformation warnings that consistently arise whenever data is added to new maps, and relegate the warning to only those rare times when data not accounted for with a default transformation is added to the map.
