So I discovered something interesting today. Apparently, the more times you do the quest, the higher the movespeed cap it gives you.
When I first started doing the quest (when it was first implemented), there was a hard cap of 30 - no matter what buffs I used it never went higher then that. As I kept going though, I noticed my movespeed was going up (to 31, then 32, etc). I figured it was just buggy, where some of my movespeed buffs were sometimes working and sometimes not.
But as I finished my 60th attempt today, I noticed an interesting difference. Even when I had no movespeed buffs on except token (meaning my base movespeed was 33), when I started the quest my movespeed would jump up to 35.
Anyways, just an interesting tidbit for your information. It seems like its designed to get easier the more you try, so if you are getting frustrated with the quest just keep at it. You will get faster and faster as you keep trying, no buffs required.