I've been following this thread with quite a bit of interest myself. However, I wonder if dividing up the lists based solely by tiers is really the best idea.
For example, choosing from UU pokemon only for the "commons" in a pack seems strange when you look at how popular some NU pokemon are. If you look at the December usage stats for standard, some NU pokemon (i.e. Medicham (#106), Ursaring (#114), Cradily (#84), Porygon2(#55) and Charizard (#66)) are used more often than some UU pokemon (i.e. Scyther (#151), Chansey (#174), Rotom (#194), or Mesprit (#141)).
Granted, a good number of these often-used NU pokemon (say that five times fast) tend to either be one-trick-ponys or only work on very specific teams, but enough people out there use these pokemon that it would be frankly a little unfair not have them be avaliable to draft.
Here's two ways one could change the lists to include the more popular NU pokemon:
1. Just add ten to fifteen NU pokemon to the UU pool - probably based on what the more popular NU pokemon are. This may make the pool size unbalanced; the number of "common" pokemon drawn per pack might need to increase (to, say, 2:3:6 in total, now leaving three unpicked pokemon after all the drafting is completed).
2. Using popularity instead of tiers to determine pool placement. For example, the 25 most popular pokemon used in standard for the previous month become "rare", the next 30 become "uncommon", and the next 50 or so are the "commons". This keeps the "rare" and "uncommon" lists essentially the same as they currently are, save for opening up a few UU / NU pokemon to become "uncommons". The "common" list would now be a mix of the better UU and NU pokemon.
Either way, I am very interested in this format and would love to play a game of it sometime!