My only problem with specific league rules like this is that they are usually not clear or might conflict with the "real" rules.
Example: Written rule on the official photocopied paper states L.L. rules except... One of the exceptions is, "Free substitutions." Pitcher is removed in the second and wants to come back in the fifth. Does the "free substitution" mean for the pitching position pitchers, too? (Both coaches insist this was discussed at the preseason coaches' meeting, but they have a different answer on the outcome.)
If the special rules are clear, I don't have any problems calling them... especially those mercy rules: 15 after five or 10 after two if the pitcher has walked more than seven. (Heck, I'll even help them make up new mercy rules if I can get the coaches to agree.)