I really like the sound of the 2x10 The issue with buying another one was that it would be too much for me to get around, whereas adding the 112 would be just about doable in a taxi (for the rare occasion I need more volume than the 210 alone) and would also give me the option of just using the 112, for smaller acoustic type gigs.
Food for thought though... seems as I suspected, it's not straightforward
I haven't made my mind up to go down this road, it's was just an idea, hence the thread