you could possibly clone them and place a 'default_approach_lit "1"' in the config extensions.
Typically the absolute signals are always on but there are some cases when they can be approach lit. Usually this is a special case and it is not part of the SmartSignal default code to allow the user to set this, other than what I said above.
Mojave sub has a few 06 and an 08 searchlight that are approach lit.