Haven't figured out where the converter is yet. Been reading through a bunch of info and poking around my rig - still haven't found it.
Typically, the converter will be installed below the load center, behind a faceplate. You don't have to find it to see if it's operating, though. Measure voltage across the house battery terminals when connected to shore power. You should measure above 13.2 V.
The latter part of your post above, quoting the Xantrex and switch user, refers mostly to his poorly operating inverter/charger and the workaround of using a disconnect switch. Don't make other folk's anecdotal system idiosyncrasies your own personal problem.