I have a 20' boat that weighs about 4100 lbs with the trailer. From the info I have gathered here, max capacity for me is 5700 lbs. However, the hitch can only support 4000 lbs. My question is, since my trailer has surge brakes, will the addition of a WDH affect the ability of the actuator to "surge"? I normally only tow this this about 15 miles a year (to and from ramp), but this summer, I will be pulling it about 600 miles. I have pulled it at highway speed of 70 before,and it pulls quite nicely. Do I really need that WDH if it won't work with my brakes?