I was going to do the 'cocktail shrimp' cycle where you just toss a few in to decay, so I figured that would feed ammonia -> nitrite -> nitrate once the bacteria were fully seeded/established, and then once there was a nitrate spike showing on the tests I could start the cycle of the denitrifier, in theory. So long as I continue to ensure there's enough stuff breaking down to feed the bacteria to continue to produce NO3.
My concern would be if there's enough nitrate to fully support the bacteria in the denitrifier in that case though. I would almost think I'm better off getting the tank at least mostly stocked before cycling it just so there's a guaranteed abundance of NO3?
For methanol version I agree, it will require many adjustments along the way. For the ethanol version, it will grow without you needing to do adjustments to the unit itself, just add more vodka as the load increases (I use about 5-7ml a week).