Nuts Poker League Rule:
New Limits When time has elapsed in a round and a new level is announced by a member of the tournament staff or
software, the new level applies to the next hand. A hand begins with the first riffle(shuffle). If an automatic shuffler is
being used, the hand begins when the green button is pushed. Posting blinds in lieu shall not qualify for retention of the
previous level.
"Dual decking" is not permitted in any game I run and neither would I participate in a dual deck game, I have used it previously and it just gets messy. The only exception to this obviously is where a shufflemaster is used and the table is dealer dealt. which is accommodated within TDA and Nuts rules.
Wolfster: Once action occurs a misdeal cannot be called, once two people have acted on their hand the deal must play out, I would therefore apply this rule to what blinds were posted, but remember when the blinds were posted was irrelevant to what what the blinds are during that hand. If say the new level is announced, the deck is riffled, dealt and the old blind level is posted, then 3 people act out during the hand without realising the level is up, then I would probably let them play the previous level. Another consideration you could make is substantial action, for example if only one player had called before attention was drawn to the level up, then you could correct the amounts before proceeding.
Regards
Stu