I'm curious about this too. (I'll be getting my HX effects in a couple of weeks and have been doing my homework on this so that I'm ready to be up and running as soon as it arrives!!)
I understand what you're saying about not assigning the send or return to a footswitch, so that you don't give up a spot....but I'm still a little confused about whether or not I will have to "give up" a block overall. I've seen tutorials where, out of the nine total effect blocks you start with, people put their 'pre' effects in, then set a block to be the send, another block to be the return, then continue on with their "post" effects. Whether or not you set those blocks to be assigned to foot switches, to me that says now you're immediately down to seven blocks you can use for effects (in other words, choosing to run 4CM now limits every preset to a max of seven usable effect blocks...) Now, if you have a second amp and wanted to do 7CM, then you'd be down two more blocks for routing so you can only have a max of 5 effects?!?
I'm very much hoping that I have an incorrect understanding about the way to accomplish the routing, basically that there would be a different way to set the routing to use/bypass/etc the effects loops for 4CM that would not use up blocks out of the nine total. (It's also entirely possible the tutorials I was watching were put out by idiots who didn't know what they were doing...........)
So, my overall questions is just: Can you route the effect blocks for 4CM WITHOUT using other effect blocks?? (Through menus/settings on a pedal by pedal basis?)
Thanks!!