Hi,
It is possible but it requires some development and PHP skills to right edit the views which display the address.
The "address_template" gives a template of what display and how.
But the "address_state" is displayed using the state custom field, which just show the state name (and not the state 2 letters code).
So, if you want to display the state in 2 letters, you will have to change how the address_template is used in the views and add a new kind of "tag" to display this 2 letters code.
$fieldsClass->show($field, $address->$fieldname) allow to display the custom field content, but it will display the state name for the state custom field.
You can access to the raw value $address->$fieldname which contains the zone_namekey, do a request in the database to load information about the state and display the 2 letter code instead.
Regards,