we have done something similar by editing the relevant xml file under ODHOME/conf/LiveSite/ (webroot something)Replace the internal farm reference by an external farm reference - and set up the farm in odnodes.xmlAs you can see, I left part of the exercise to you ;-)PS: if you are also using a farm of LSCS, it's similar, but a bit more elaborate.
Got a solution from support and I think it retains the flexibility you mentioned. Hople it helps.