I think challenger finals is not a very good format, having one tournament decide all might lead to best teams not making it to masters.
i would much more like to have circuit points. for example you have 2 or 3 challengers where u get cricuit points. challengers finals is then made up with the finalists of all challengers and the remaining spots go to the highest circuit points teams. then challengers finals the winner gets to go to masters and the remaining spots could go to the highest circuit points. that would also make the challengers more competitive and fun to watch
it works similair in rocket league hope the format gets better