The default position for the button that closes a window is in the upper right corner of the window.
Dear user, this wish list item is now closed, as it wasn't touched in the last two years and no contributor stepped up to implement it. The Kate/KTextEditor team is very small and we can just try to keep up with fixing bugs. Therefore wishs that show no activity for two years or more will be closed from now on to keep at least a bit overview about 'current' wishs of the users. If you want your feature to be implemented, please step up to provide some patch for it. If you think it is really needed, you can reopen your request, but keep in mind, if no new good arguments are made and no people get attracted to help out to implement it, it will expire in two years again. We have a nice website kate-editor.org that provides all the information needed to contribute, please make use of it. For highlighting improvements our user manual shows how to write syntax definition files. Greetings Christoph
Thanks for auto-close :) For me, the issue is not solved, but it needs a more general discussion before doing something in kate alone. So I started a discussion here: https://forum.kde.org/viewtopic.php?f=285&t=130864&p=350716