Could there be a category for all the maps in one run? There could be sub-categories for each of the difficulties, doing all runs in that difficulty, as well as one for all of the runs. I'd imagine it has to be done in one sitting, but I'm not too sure how the time for the runs would work with loading times and possible ads.
I saw in the news that there won't be a category for the hard levels, because the levels are basically the same, but the lines are completely different, making the times for the run different as well. I can understand not adding an Any% run for them, as the times would be the same, but adding a 100% category for the Hard runs would be different (and much appreciated)
Even if it's just one decimal, milliseconds would help a lot with the times, lessening ties