Suggestion is to give Conduits the option of making wormholes one-way or two-way at the time of opening.
I've been considering this one for a while. The means to somehow manipulate wormholes in the same manner as wells/sinks seems appropriate. Initially I thought of closing any open wormhole at half the cost (5 AP, 10 MP), your own or someone else's. IMO that might be useful regardless, but a more subtle option for varying wormhole types should also be doable as the code was originally one-way only.