LN2 is not viable, it's probably a good use for all the hardware made for the AMD CPU's, the old vapochill boxes, but the ASIC chips would probably struggle with the whole peltier setup needed, with no payout, and really hard maintenance/setup. like, 5 hours of your life you'll never get back.

a peltier cooler would be an easier sell, less "ahmagaawd, this is cooool".

maybe there's some benefit to a better cooler ...

let's see, you could use off the shelf copper heatpipes, fin radiators,

or, if you have a thermal cooling efficiency problem, e.g. too much heat, not enough space, e.g. rack mounting ASIC blades, or something,
water/fluid loops and 120mm radiators, much like the corsair / swiftech contained radiator loops.

it's relatively cheaper than a custom fin solution, and able to be chained in a bigger radiator solution, i.e. rack cooling with quick disconnects,

a combined pump off a 12v connector, so you can design a vent/radiator to rack-mount a bank of ASICs to cut down on ducting and fan noise, set each blade/rack to use rows, pump fluid in at the top and bottom, and parallel cool & pump 8-10 racks

.. for no particular reason.

one can dream.