I would have liked to see that capability too --- I'm not entirely sure how much difference I would notice but like you guys, I don't like those two unused amps just sitting there.

I can understand not adding the capability for multi-zone with the rear surrounds due to extra complexity and cost, however I think the complexity of adding bi-amping depends on how it would be done.

If it's just a matter of always sending the same signal that's sent to the font l/r to the lb/rb it might be pretty simple. I can see just another config option on the SPEAKER SIZE - SURR BACK OUT: selection to choose between NONE SBL LB/RB BIAMP. This might even be possible with a software update.

However, if there's a need to introduce a crossover so that the L/R gets a low-pass signal and the LB/RB gets a high-pass signal, this can get pretty tricky with the variety of bass-management options already on the 1070. I think this would only be useful if you could defeat the internal crossover in your speakers (which I can't in mine anyway).