I'm trying to set a datetime2(0) column to show the time in 12 hour format. Per this KB article, I entered g as the format string. While the column does change in the grid view, it just switches from MM/dd/yyyy hh:mm:ss to yyyy-MM-dd hh:mm:ss.
With no format string:
With g as format string:
Tested in SSMS:
As a separate but related feature request: Please add an option to apply a field's formatting on the form view as well. I understand the rationale to have the default be no formatting, because it may hide information or make it difficult to edit. But it would be nice if administrators had the option to override that setting.