Bulge '44: Should the British cross the Meuse?

[dto]

Playing PBEM in Bulge '44 Alt Campaign. Is there a specific rule that the British shouldn't cross the Meuse? I seem to remember seeing that in one of the campaigns.

My personal feeling is that especially in an Alt Campaign, where the Germans can do better than history (like taking St. Vith early), then the Brits should be able to cross the Meuse. However, if the consensus is that this would sharply tilt play balance against the Germans, then I would prefer not to use it.

Michael