Consider that some now are arguing that Deoxys-S should have been allowed in the beginning of DP so that we would have quickly known its brokenness or not.
Alternatively you could consider the people arguing that there are now too many pokemon and are calling for a metagame/s with reduced numbers of pokemon ... NFE's provide a convenient and obvious place to begin culling.
Why not include NFE's in UU as early as possible to examine their impact on the metagame?
Were there actually a UU metagame to speak of I might agree, however at present the "UU metagame" is limited to an extremely small number of players. Therefore at present one of the more immediate goals should, IMHO, be to try and encourage more people to play UU.
From speaking to people on Shoddy battle I am conscious that the size of the UU tier is one of the factors that puts people off playing it, as, for whatever reason, they are reluctant to learn the potential movesets and strategies for 100+ pokemon. Is it worth discouraging them further so as to test the impact of pokemon that may or may not have any impact/see any use?
Manageability means that you feel that you currently can't keep track of all the threats in UU? You might be able to have this problem when the upper edge of UU overlaps greatly with BL as it does now, but how can one be confused as to what an NFE is?
Why is managability simply limited to the threats? At this stage all of the pokemon require a degree of monitoring so as to allow for current, relavent analysis.
I'm confused as to what you meant by the bolded section.
You suggested that the blanket ban was extreme and unneeded, I suggested that the sheer number of NFE's might be a significabt factor.
However if you don't feel that I understand the term NFE perhaps you could offer your understanding of what the term means to you and we can go from there ...
*WIP*