Auto precision may lead to unintended edits. There is no precision named auto stored in the value. But it is also not possible to manually select a precision and make it stick. When editing a value like time or geo the precision changes without user intervention. You can make it stick once when editing, but after saving and then editing again it is back to auto again. When this is changed the visual hint for auto or precision also needs to change.
So if you edit a value that has a manual precision set that is different from what auto selects then the precision setting is reset to what auto selects.
For quantities this will be done with: T115269: [Story] When a Quantity is entered with no uncertainty/bounds given, do not guess uncertainty/bounds until needed.
For geo currently a null or 0 value for precision that will be used as 1/3600 on formatting: https://github.com/DataValues/Geo/blob/f4627f6fd6ed2bb7f59054f7af7a2c75aaebf407/src/Formatters/GeoCoordinateFormatter.php#L130