I see what you are saying and maybe it would be best for OP to help us identify what the "uglies" are. Is it diatoms? Dinos? green algaes? if we can name the uglies better than the uglies we may be able to get to a better idea of what is going on.The part of the experiment that confuses me is the use of cycled rock out of an existing system. Without understanding that system it will be hard to make any assumptions about this system. "The Ugly Stage" typically refers to tanks that are started with dry rock and sand as they need to build up the biome that will out compete what people consider to be ugly organisms. If you use cycled rock Live or dry in a new system you can circumvent the ugly stage of a new tank which is why new tanks in the past that used live rock out of the ocean didn't typically have an ugly stage if the rock didn't have much die off in transport.
If the experiment was to see if you can start dumping nutrients into a new tank that has rock with an established Biome then it makes sense.
I just started a 300g tank with 160 pounds of dry marco rock and 80 pounds of established rock (it wasn't from the ocean but it was in three different well established reef tanks so lots of Bio diversity) There were no ugly organisms on the 80 pounds of cycled rock and the 160 pounds of dry marco had lots of diatoms on them until the biofilm was established which took about 6 weeks. At 8 weeks I am now seeing lots of coraline growth and the only ugly I have left is some cyano bacteria on the sandbed which is a result of me keeping the phosphate levels higher to help drive algae growth in the system (Phosphates are about .13 ppm and nitrates are between 2-6 ppm and I measure them daily right now). The tank had 20+ fish added right off the bat so a large nutrient intake and lights were on full from the beginning 150-200 par on the sand and 300-400 on the rocks.
I'm listing this out to show you can circumvent alot of what people consider the uglies by using cycled (dry or live) rock from the beginning. I also wanted to point out that the largest contributor to the results is not the nutrients you added but the fact you used established rock from a different system which is something I don't see called out much in the thread.
OP would you mind sharing a final shot of the aquarium. What did your tank eventually become colonized with do you think? thanks.