Uhh, you don't have to switch your stereo tracks to multi-mono... they already are. When you are selecting the plug-ins, instead of selecting from the Stereo plugins list, select the multi-mono list. Then you will see EQ3 there. It's still stereo, and it still works in stereo. I'm not sure why Digi did this, but it is no different from a processing or usage standpoint from using a stereo plugin, except that if you want to, you can do the EQ differently on each side (but this is entirely optional, and by default it is just plain old stereo).