This might be a bit off topic but i will answer my own question above in this thread.
I bought and tried a Ducky 3 yesterday. I found out that the second level repeat delay is just as fast as the windows max, that being about 250 ms repeat delay. The third level however is significantly faster, probably around 70-80 ms (my estimation). This is simply too fast, i tried playing with it (SC2) but ended up double tapping every now and then against my will. Why the hell does it go from 250 ms all the way to about 70-80 ms? Where is my perfect 120 ms option?!

Btw the 4:th repeat delay level is pretty much instantaneous repeat, its really hard to achieve a single press with it enabled, the repeat delay is probably around 20 ms or so.
So, if you buy this keyboard and want to benefit from a shorter repeat delay the option that is about 70-80 ms is your only alternative. Simply too short of a repeat delay. I will return the keyboard as i have no use of it.
Btw i have not mesaured the repeat delay levels, but i have used a software before called "KeyBoard King" where i for fun tried out all different levels of repeat delay, so i got a pretty good grasp of different repeat delay speeds (and could tell that about 120 ms would be my optimal speed of repeat delay). This software does not work well at all in most programs though, but is great for testing.