First of all, let me get this out of the way- I am in no way suggesting shield sharing with turrets or via axes. This suggestion pertains only to non-rotary, linear-sliding rails.
With the amazing rail system being worked out, this seems like a necessary addition. Unlike turrets, things that are attached via rails are largely treated as components of their host, rather than as (mostly) independent ships that happen to be stuck in place. Thus, it is only reasonable they should enjoy the same protection as the structure they're a part of. If anything, it's outright necessary for any external placements. And who wouldn't like to see retracting bridges, sliding hangar doors, or why not entrance elevators?
With the amazing rail system being worked out, this seems like a necessary addition. Unlike turrets, things that are attached via rails are largely treated as components of their host, rather than as (mostly) independent ships that happen to be stuck in place. Thus, it is only reasonable they should enjoy the same protection as the structure they're a part of. If anything, it's outright necessary for any external placements. And who wouldn't like to see retracting bridges, sliding hangar doors, or why not entrance elevators?