Why is it bad if beer freezes? I know it can make a chill haze permanent, but if the beer doesn't have chill haze, what's the risk in freezing it solid?
I've had some damn good Eisbocks.
Since the amount of lagering time needed seems to be dependent on temperature, maybe all you really need to do is freeze the beer solid and then thaw it out and put it on tap.
Autolysis. Yeast cells explode or are pierced by ice crystals, releasing the yeast's guts, which can give your beer a meaty or brothy flavor -- not usually desirable characteristics!
I've had Wyeast Smack Packs freeze up on me during shipment in the winter, and I was still able to thaw them, smack them, and get a healthy fermentation out of them. According to Lalvin, you can store dry yeast in the freezer. I'm not sure that a short freeze and thaw cycle would lead to significant autolysis. Although, if I were to try something like this, I'd probably want to get it off the yeast cake just in case.