It's probably to find anywhere, but the search was only coming back with mapping topics about midi lights and not the actual mapping so here we go...
I really really like to switch between 2 different blending modes on a layer, Add and Jitterbug, and I really do use both a LOT, on R5 I had 2 buttons, one to switch to Add, the other switched to Jitterbug, now those buttons are gone in favor of a pull down menu, which I also find back in the mapping info when mapping is on, but I can't get it get to work, not toggeling with one button not switching with two, nothing.
Also I cannot map 2 buttons to 1 button in R6 which I could in R5 using both mapping modi.
Personally I am really really confused about the whole mapping thing and even with the manual opened on another screen and trying things I can't get it right, where in R5 I walked thru in a minute