Thanks for the info, Jim. I've wondered about this for a while. Finally broke down and brought it up.

Retried everything. Cannot reproduce. Works as I'd expect, as follows:
 
 
A mono-recorded track, mono icon showing, drop Sonitus or LP-64 EQ in FX bin, only one line at bottom of button.
Process as discussed. Result: mono.
 
Same for stereo. Shows two lines under button, result stays stereo.

jshep0102
I'm beginning to think this could be handled in a more 'mixing desk' fashion and be more predictable/understandable.
 You have mono channels and make stereo channels from them. The way audio actually is outside the box.

You can work like this if you want to, but obviously can't slap a stereo compressor (say) on the "stereo" channel without using a bus (hmm...or a new patch point perhaps?).

At this point in time, it should be doable either way. I typically have use for a comp in more than 1 track, so the bus is the way I do things a high % of the time. I like my resources at my disposal.