Do you mean at all, or that the offensive in the west still occurs but is better executed in some details?
If you want no changes at all there is still a lot of unrealised opportunity for the Navy in Flanders from late 1914 onwards, histories of both the Dover Patrol and MarineKorps Flandern agree on this point. Coast defense battleships and destroyers could have made the Dover narrows a real war zone for little opportunity cost for the German. In contrast countering this threat would impose significant impacts on British war efforts, either to accept the risk and losses or limit some other activities to provide resources to defeat the stronger than OTL German naval forces
In perfecting the Schlieffen Plan I feel I am just stepping in the same path that began just as soon as the General Staff needed a scapegoat for its failures. You and a few others have tread that ground, in part I want to take the other road, the Western Front is at least generally known, the East is a virtual black hole beyond these pages. In moving East I simply use the existing doctrine and plan for the Battle of the Frontiers, hold 2nd and 3rd Army in reserve, rely on the counter-offensive, absorb the French and then break them, hopefully capturing the men rather than letting them slip away before the conquest of dirt. But if I were staying West then your treatment of Flanders is informative of what more could be done. In fact I keep it back of mind for just how much more poorly placed the Germans are having moved East, the HSF is that much further from the war.