Not sure whether this is really a Feature Request or not.
There are two things I occasionally want to do with a template: edit and delete.
At present, if I want to edit my default template, I open a new file, make the edit, and then save as template. I have to rename it although what I really want to do is just save it without renaming. If I rename, I end up with the new file that then has to be designated as my default and an old one I no longer need.
All that might not seem too bad if deleting files were easier. But I don’t think you can go into the template picker and delete from there. You probably have to navigate to the original folder and do it “manually”.
I may just be doing all this wrong. If I’m not, then I guess my Feature Request is to make it possible to overwrite a template without renaming or other faffing around, and to make it easier to delete templates in one central location.