Good spot, yes the previous model 200 had a second cranking battery, yes two, with the second located where I now how the auxiliary deep-cycle. A change was made at Toyota and that second cranking battery was removed which made it much easier to out in the auxiliary. It's also possible to put a tertiary deep-cycle actually, but I don't need one.
I've been away for 15 days and stored enough old food in the fridge to be eating fresh food on the last day. 60L is a surprising out of room if packed correctly.