These are tough to discuss because so many factors enter into it. It had crappy range, so I am not sure how much an impact it would have had on the Battle of Britain.

Also the US and UK came up with tactics fairly quickly, and this would have mostly nullified any advantage (the 262 was faster, but the P-51 and Corsairs were more maneuverable).

Furthermore, the US and UK also probably would have come up with their own jet technology fairly quickly if forced to.

In the end I would say probably not much. The US and UK had far more resources and safe areas to operate them from.

Of course an argument can be made for a serious change, based on further assumptions regarding increases in range and further development. But additional "what ifs" really become tenuous to argue.