I do not think that it would kill the trip, I think it would make the trip appear less dissociative, when ketamine binds to NMDA it binds to the glycine site and do nothing, preventing glycine to bind and do what it does. For NMDA receptors to open, it needs 1 glycine, 1 glutamine and for the neuron to have a certain level of action potential.
What noopept does in this regard, is to activate AMPA receptors which raises the action potential so when there is glycine and glutamine it is easier for the NMDA receptor to fire, altho if a ketamine molecule is linked to the glycine site it doesn't matter that the action potential is raised because 1 of the 3 things needed is missing.
What I think it does is let your brain activate other cell's NMDA receptor more easily which would reestrablish some of the cognitive abilities that Ketamine would have blocked, but the cells that are blocked are still blocked. It also help acetylcholine system which is also blocked from Ketamine so I think the same effect happens regarding Acetylcholine receptors and NMDA receptors. So the overall effect on neurons is the same but the effect on cognitive abilities might be reduced, altho the ''euphoria'' if there is any and the painkilling abilities are IMO still going to be 100% perceptible.
Altho I think it is quite contradicory to use noopept and Ketamine, since noopept increase cognition and ketamine reduces it. So I do not think it kills the effect but I can't see why to mix them. Well there is the serotonin boost from noopept that can add to the SERT reuptake inhibition of ketamine but I don't think most people use ketamine for a serotoninergic effect so still don't see the point unless you are trying to fight depression in an odd way.