Load Balance & Proxy

ROS 3.7, RB532A, 16GB CF
I’ve implemented the load balancing example as in(yet to be tested properly with 4 WANs):
http://wiki.mikrotik.com/wiki/Load_Balancing
But would like to add transparent proxy. Is it a simple matter of adding a dstnat rule as in:
http://wiki.mikrotik.com/wiki/How_to_make_transparent_web_proxy ?

Or is there some other things I should keep in mind in combining these two things?

Thanks
Ekkas