Just to correct a misconception here - Peacock at 60fps is not '10fps better' than K+ at 50fps, rather you want your stream's frame rate to match the original frame rate as closely as possible. So if you are mostly watching UK content, you want your service to be 50fps. If you are mostly watching American content you will want 60fps. The cameras in the stadium are running at 50fps, so you aren't getting actual extra frames by watching the match on Peacock. In fact converting from a UK source to 60fps will reduce the quality because it is having to interpolate frames and this will introduce motion artifacts. Having said that the difference is pretty hard to spot - I am happy enough watching the Peacock streams and don't find it particularly distracting that it is using the 'wrong' frame rate. But if you have a choice between 50fps and 60fps of the same quality, you want to choose 50fps for the footy.
As far as K+ I am in the process of signing up to check out what the quality is like, so thank you for the sign up guide, very useful, and fingers crossed the quality is decent, it looks like great value if all is good.