Thanks DI, that does clear up not only the current implementation confusion but also the way you see it "if" implemented.
I also note that you are talking about the "remote footswitch" being the feature being exposed, which obviously inherits some "HELIX CORE" functionality/baggage...
not an FX BLOCK control... all makes sense... all fits with the product line(s)... but could be improved... ;-)
Having done some checks this morning I think I have answered this...
1) The "mode" (studio/direct:combo pre:combo post:stack pre:stack post) is done right at the end of the POD HD signal chain, just before being presented on the "outputs" (either the Balanced or Unbalanced)
2) In order to run BOTH a sim amp and a real amp, you need to tap off the signal for the real amp by using the FX Loop Send. (the FX loop can be placed anywhere in the chain) to get desired result.
(btw NucleusX, I want to have POD HD effects before the amp so the dry out is not an option)