Something else came into mind, namely the enormeous number of torpedocraft in the Hochsee Flotte. Germany had lots and lots of these nimble and fast craft, all capable of operating in the North Sea, as it was considered the most likely battlefront at sea. The original scenario only had included relatively few of these craft and units, so most likely there would have been more.
Normally in this late period of the Great War, the most likely compossition of the Hochsee Flotte, would be composed of fewer large capital ships, most likely ommiting the oldest and slowest Dreadnoughts and especially the Pre-Dreadnoughts, in favour of more flottilla's of torpedoboats lead by a few fleetcruisers (normally light cruisers, supporting the little torpedocraft, especially against British Destroyers.) These vast numbers of trorpedovessesl in the later war Hochsee Flotte could deliver a serious punch against a slow moving battleline, which only in theory could sail at 21 knots. (Coalburners rarely even reached this speed, due to their labour intensive powerplants.) Especially the USN first generation Dreadnoughts were disappointing in this, being fitted with unreliable engines and often much slower than designed. So the 6th BS would still be a burden, rather than an asset, given the generally faster British designs. (British Dreadnoughts normally exeded the designed 21 knots in theory, and could still do quite well, being equipped with more reliable turbines, while the 20 knot designs of the first ten USN Dreadnoughts, rarely got more than 18 knots out of their vessels, due to their temperamentfull engines.
I suggest to let teh USN squadron be included in the slower Pre Dreadnought groups in the south, rather than having it in the Grand Fleet. Perhaps even joining up with the equally slower French Dreadnoughts, when these would be present as well. The 5th BS of the five Queen Elisabeth class Dreadnoughts should also be sailing on their own, or with the Battlecruisers, being much faster and better equipped to deal with the German battlecruisers, who were in most cases superior to the British battlecruisers. The pressence of the Queen Elisabeth Class, with the battlecruisers could be very impacting.