According to Wikipedia "In November, six B-29s bombers from SAC's
43rd Bombardment Group were deployed to
Rhein-Main Air Base in Germany, and for nearly two weeks they flew along the borders of Soviet-occupied territories and paid visits to bases of friendly countries, including the UK, thereby evaluating their suitability for future use.
[7] None of them were
Silverplate bombers capable of carrying nuclear weapons; the US had only 17 of these at the time, all of which were assigned to the
509th Bombardment Group at
Roswell Army Airfield in
New Mexico.
[15]"
Seems like any visit to Burtonwood was of very short duration, perhaps just to refuel and prove the B-29 could land and take off from there.