I hadn't thought about that, but it's possible and perhaps it's tuned for higher frequencies then I'm currently using. We'll see pretty soon. After I get a few more chips mounted I'll add a heat sink and bump up the clock. I think my plan is to add one more on the same bank, and then after that two more on the opposite bank.
About that heatsink. Isn't it true, that avalon chips must be cooled from below? I mean you cannot put heatsink on top of the chip, but below the PCB with silicone thermal pad. It's just like block erupter is cooled.