Kmymoney and Plasma

When will kmymoney go to kf6 and qt6?

There is currently no proposed estimate, timeline, or schedule for this. There may or may not be a 5.1.4 release, but most of the current development work is aimed at a release currently labelled as 5.2, hopefully early next year. That version will include a number of bug fixes and new functionality, as well as some significant changes to the internal workings of the program. After that, I believe that most development effort will focus on the support of KF6/Qt6.