Only ±6% BPM?

Hey folks. Is there any reason I can only choose between ±6% BPM for matching tracks on the XDJ-XZ? Why is 7 8 and 9 shown if they're not selectable? The tempo faders go as far as ±100 with wide selected, and you can choose related tracks as high as ±30 in Rekordbox. This is present on my XDJ-1000MK2 as well, I would assume the CDJ's have the same design flaw. Is there any reason this limitation was programmed?

If not, please forward this to your developers as I can't imagine it difficult to rectify. I found another post about this 2 years ago, to which someone replied they would report it but nothing has changed.