Hello!
I am currently working on an online platformer, and many players are giving me feedback about inconsistent dash distances, both for them and for their enemy. 
For movement, I just use the integrated Platform behavior and not using any DT at all in that event. 
It works like:
On Button pressed: 
 Set dash to 1
If dash == 1
 Simulate pressing right/left
 Add 10000 to acceleration and deceleration 
 Add 200 to speed
 Wait 0.1
 Subtract 10000 from acceleration and deceleration 
 Subtract 200 from speed
Do I need to consider adding dt somewhere?
Might it be that acceleration in Construct doesn't consider delta time?