I can only give a partial answer here. There is some hint of this in the original CRV manual.
It's a question of keeping the subconscious or "detecting truth" part of the mind uncontaminated. You do a set aside or declare an AOL after you get a noun. CRV and SRV are in agreement on that.
The stated reason for this (from the CRV people anyway) is that the analytical part of the mind can't really help but jump in and give an answer with whatever bits of data the sub provides.
This is a constant human activity really, with the mind having to predict what the "present" is, because it takes about a tenth of a second for al the visual data received to be processed into perception. Stage Illusionists exploit this as "sleight of hand, the hand is quicker than the eye".
So, once you get a noun that "feels" very close, it's very hard to shake it off and try again to unravel the truthful elements of what the received data from the ongoing human churn of analysis. RV was built as a tool to be used for many different real world applications, and the thing with RWA is, there is only a limited amount of resources to spread around particular projects.
There's probably a lot more going on here than I'm aware of. At least, this answer I'm giving only "feels" like part of the truth to me.
But it's the best I can do right now. And it's reminded me that I wanted to do a little more work on Tazz' target, to break out some more data from the declared "something not right with this" data impressions. So thanks for asking.
