Linked object modifiers

As of right now, it is impossible to add modifiers to a linked object. I do understand the reason for this, as there may or may not be modifiers on the original object, but it seems like it would also be fairly simple to have two groups of modifiers. (If I remember correctly, modifier groups are in the pipeline?) One of these would be the modifiers on the original object, and would be greyed out. The other, however, would be modifiers only present in the current .blend file, added aditionally to the modifiers already present.

This may seem trivial, but as of right now I am working on a sci-fi esque rail system where I have all of the components in seperate .blends, so I can edit them completely independently, but for the rail system, I am giving the base rail an array and follow curve modifier, so I have to delete, reappend, and remodify every time I want to update the scene.