Edit: Im afraid I need to correct myself. Valve did remove the command alright, but they didn't actually remove the function. They just made it only work when you set up gamepad controls via the Steam Input thingy that they enhanced in the latest Portal update. So it's still there, they just removed the feature to set it up manually and since the mod sets up controls directly in game the and not via Steam Input the game just doesn't detect the flipped portal fire binds.
In Lost Coast, I didn't edit client and server libraries from the beginning, and didn't include them before because of that.In portal I copied the whole \"bin\" folder with engine dll and etc. This one was used for other versions of the mod. 781b155fdc