This is a really bad situation. Why are the keymaps you set yourself in some way overriding what is set in the presets? For instance, I have several custom keymaps set up. As soon as I change something that is not like the builtin keymap that I based any of these on, I have to manually set the keymap for this interaction in all other keymaps!
I’m not sure on what level this makes sense. For instance, save a new version of the “Blender” keymap called “My Blender” Change the view rotation keymap from mmb drag to alt mmb+drag. Now switch back to the “Blender” keymap. The view rotation keymap is still set to alt+mmb. This means that any time I want to make a new keymap, I can’t simply switch back to the default blender keymap without manually overriding the changes. I want to see if what I made is better or worse, but I’m having to do all of these extra steps to change it.
People expect presets to bring you back to default behaviors when ever you want to, but that is just not the case with blender’s keymap presets.