Some instruments, like BFD3, have key map of it's own and it's nice because it automatically loads the key map into the Studio One drum view, you can then customize it further like assigning colors and changing position, but you can't save your customized drum map into an instrument preset, or in any way whatsoever, and everytime you re-load the project, the third party instrument's own key map will overwrite the changes you did in Studio One.
I wish there could be a way to customize this.