I have taken to shifting interfaces/drivers a bit during mixing and it appears the Prefs->Audio->Audio Profiles (visible when in WDM/KS mode) "resets" the DMA Buffer Sizes each time driver mode is shifted to WDM/KS.
 
Storing any such profile adjustments would be highly beneficial. As they "reset" each time, insight into if those default values can be overwritten would also be helpful.