as a general rule, his tunes don't alter the speedo settings. but there is a 'speedometer calibration' that you can do. if all the gear ratios and specs are the same for the breakout as they are for the touring models, i can give you what the numbers are on mine.
just looked on the hd website. the gear ratios for the 2018 breakout are not the same as for the 2018 touring. if you want, i can still give you the correction factor, or whatever it is they call it, but probably won't be exactly right. but it would show you whether or not that's going to work....
if you pull up your map, under the 'gear' section, there is a 'speedo calibration'. mine has 2127 pulses per km. you might try changing yours around a bit to see if that does anything. just remember what your original value is so you can change back.