Do high efficiency condensing boilers with built in outdoor reset still require a mixing block?

I am considering getting a Weil Mclain Ultra boiler. It has built in combustion modulation and outdoor reset. With the outdooor reset built into the unit I am still wondering if the need for a mixing block on the distribution panel is necessary. I know that mixing is needed for atmospheric boilers to prevent thermal shock, but condensing units are still new to me. Any knowledge would be greatly appreciated.