(Reposting, since the original was lost in the conversion to flow)
The process as written here seems to imply that a feature, even a large one like VE, would go through all the phases, roughly in order, as a single effort. Basically it would culminate in a "big bang" release of the whole thing, months or possibly years after the initial conceptual work was done. That contrasts sharply with the agile and FOSS approach of "release early and often".
I believe (as do most agile and open source practitioners) believe that whenever possible, small increments of work (at most a few developer-weeks of effort) should move through all the phases, including release, so that real end-user feedback can inform later increments of the same major feature. I hope that is how this was intended to be used, but if so, it needs a fair bit of clarifying text. If the intent is to shift to a more waterfall-style development process, then that's a whole other discussion we should have.