It gives move speed for a fraction of a second after a dash rather then 50 decaying over 2 seconds.
#Pretty sure Turbo booster is bugged
harsh garnet
rotund iris
It does work on Joule, Beebo, Crysta, Bishop, Brall & Myth.
Seems to be two categories:
Joule gets boost at the end of her the dash
While everyone else here has multiple dash charges.
For Shiv, it only works during her ultimate (When she has 2 dash charges).
Same thing happens with every movement power, including glider jet, which does have multiple charges.
And express delivery, which also triggers on release, similar to Joule dash.