When we participated in the "What Is Hot" competition done by Tardon Feathered, we sent a bunch of material through the Optimod. It was 100% clear that the higher the RMS, the more distortion came out of the Optimod, but there was NO difference in perceived output level no matter how low your source was, and sources ranged from about -16 dBFS RMS to -3 dBFS! So, make a nice sounding recording that is not purposely hot---just compress it if necessary to sound good, and stop there. I'll bet you this will fall around -14 dBFS RMS for typical rock. And will sound better on the radio than hotter stuff, at least if you believe our Optimod tests.
BK