When I contacted EqualIzer, they told me that having a WDH at a higher rating is not an issue...
The system is made for UP to 1200lbs or 1000lbs... doesn't mean you have to be on that number to use it.
Once well installed and well leveled, just the appropriate weight will get distributed.
If it's not well installed, then yes, you could be putting too much pressure on the Aframe.
2014 JayFlight 28BHBE (replacing a 2009 Kodiak 25QS)
2011 Sierra SLT CrewCab 4x4
1200/12,000 Equal-I-Zer Hitch