I will give an example: Black sends "new game". He knows about his game parameters. White does not know these and tries to acquire them through queries sent to black. Gifu regulations allow (and require) exactly two of them ("what's your color" and "what's the handicap"). The board size, e.g., must not be queried, and is thus implicitly assumed.
Now I can either follow the Gifu regulations and end up with an incomplete bridge, or I can attempt to write a more complete mapping of functionality and will have a program which cannot be used in the contest.
One approach would be to toggle the two behaviors with a command line switch --gifu to the bridge program.
Or allow parameters to be passed to the bridge at the command line and only parameters not explicitly set are negotiated through the gmp.
If you really have to decide between a generally useful program and one useful just for gifu, bear in mind that Arend has written to them they can use CGoban and GNU/Linux. (I have not seen any response to his message.)
Dan