First question I guess would be, from where do you have n-oxide in the first place, and how can you be sure its really n-oxide? I think a lot of people just equate yellow with n-oxide, but thats just suppositions, AFAIK there hasnt been a single chemical analysis to show this. I think burnt's FOAF was considering synthesizing n-oxide to have a reference standard and then analyse mimosa/extraction yields and see if n-oxide is really present. Maybe yellow is partly n-oxide and partly pure dmt? Maybe its plant oils and dmt? Maybe its all of these together? Maybe it depends on each particular batch and cant be generalized?
Also it can happen that one has an oil resulting from evaporating a non-polar solvent, and then people think its n-oxide, but it can happen that just redissolving this in naphtha and freeze-precipitating will result in dmt crystals again. It is known in chemistry that even with the same material and purity, different conditions can lead to very different results (crystals of different kinds or oils).
One idea to make n-oxide is to mix it with hydrogen peroxide, but its still unknown if it works as well as theory said, maybe theres still unreacted dmt? Until we get a reference sample and analyse these things with chromatography, we wont really know
Also another thing to be taken into account is the potential self-suggestion when people are experimenting with different products. They think a dmt is different, hence they feel it. Personally, I can have completely different experiences even with the same batch in the same set and setting the same day, so I always found very very strange and am skeptic when people claim with so much certainty that jungle/yellow/whatever results in such and such kind of experience with such and such kind of visuals. Hence why I suggested
this blind testing protocol, but so far it hasnt been put into practice yet (except once by Ice House who couldnt tell the difference between yellow and white)