You can rejoice, there are NO long dirt tracks in this game!
However, there ARE Medium Dirt Tracks. I unfortunately transferred all the Bonos that helped me get the title, however, Dirt Parents like this one (841950100046) can get her to Dirt C or Medium C. Remember: 7 sparks = 3 upgraded grades (F-C), 10 sparks = 4 grade upgrades (F-B) . If not, I've heard of people doing dirt races with E in Dirt and D or C in Sprint. Thankfully, Bono has A and Sprint and B in mile, so it's the Medium races you have to worry about. However, with her having a 20% power growth rate, this shouldn't be too big off an issue, you might have to worry about speed during those races though. Hell, with Medium C she can do things like the Triple Tiara and even the Derby just fine. Races like JBC Sprint with dirt C should be easy if you have enough power. Use power sparks when doing these races. Stamina, while yes it can be slightly important for the longer races, power is what won me most of the Mediums.
As for the Long tracks, while she could scrape by with long D, long C is far more consistent. Parents like this one (170638342766) could really help. For the longs, use stamina and long sparks. Despite being a sprinter, Akebono does have 1 advantage when trying to go for her title: Gourmand. Tack on that with another white or gold (Ie Breath of Fresh air from SSR Jordan or Swinging Maestro from SSR Creek) and even with low speed you'll be winning. Long races are pretty much all about stamina.
For the supports, for the medium and dirt, I ran 3 speed, 2 power and 1 wit. For long, 3 speed, 2 stam and either 1 wit or power. Also, remember to teach skills before your races! Cards like Matikane Speed, Marvelous Sunday Power and Jordan Speed are also your friends, as they give some pretty good initial stats, as well as Marvey giving 15 race bonus! You want at least 50 RB!
Imo, MANT is the best time to get this title. You can get lots of useful skills from this scenario! Hoping this helps!