Shoot-Through Line Identification (121)?

[SickSadWorld]

Is there a way to make a Line Identification (121) (ie. a bridge etc) to be shoot through?

By default it seems to absorb all shots. It seems like there is this dichotomy between using a Line Identification:121 as a railing and just using an impassable linedef with the same texture. Naturally there are functional consequences to each choice, however in many cases the ideal behavior would be a Line Identification that you can shoot through as well as stand on.

Is there a way to get the best of both worlds and have a Line Identification you can shoot through? This seems quite obvious but perhaps I'm missing something. I'd rather not try to re-invent the wheel using ACS if there is a simpler way. That's why I humbly request any insight the community can offer in this regard. So far google has been fruitless.

[CutmanMike]

So a line that uses the 3d mid texture flag, that you can fire through? As far as I know it does not exist.