We found the old 1 Foot DACs that shipped with the MAS switches worked with the allow-unsupported-transceiver on 2930F switchs with serial numbers in the CN69 range, started to experience light errors on switches with serial numbers in the CN6B range, and would not even consistently come up and were heavily errored on switches with serial numbers in the CN76/CN77 range. We have some CN79s untested for this yet, but beware if you have been reusing these DAC cables and you blow a switch, bring new, better DAC cables with you because the replacement switch may not like older "off-brand" DACs.
(These results all with firmware WC.16.03.0004)
You'd be best advised if using 3rd party DACs to test them beforehand in the lab. We had to order several samples to find one that worked, even with the allow-unsupported-transceiver command.