It seems like moving to marks doesn't work with delete ('d') or yank ('y') and potentially other commands with movement modifiers. Is the ` not considered a motion command? Could it be/is it easy to modify for myself. A common technique would be to mark the end of a function and then delete from the beginning of the function to that mark. This doesn't seem to be possible unless I'm doing something wrong.
Also the `` command which is supposed to take you to the position before the last jump doesn't seem to work.