The OP raises several questions which I have not seen anyone adequately answer. Here's what I'd like to know:
1) Cap carryover is optional. Teams must advise the league of their intent to do so. What are the benefits/incentives to not carrying over cap vs. actually doing so? We might deduce the answer to that question if we had the answers to the following questions:
2) If you don't carryover cap, does that money go into a bank that can be used as carryover in subsequent years? Or is it permanently lost?
3) Can a team execute a partial carryover, or is it an all or nothing proposition? If it is a partial carry over, is the remainder permanently lost?
4) If you do carryover cap, but you don't use it in the current year, is it then available for carryover again to the next year? This touches on the OP question.
5) ThxJack noted the 89% minimum payout under the new CBA. The interesting thing is that the provision calls for 89% of the cap being paid out in cash, as opposed to a cap hit of 89% of the cap. The question here is whether it's 89% of the base cap (e.g., $123 mil this year for all teams) or is it 89% of each particular team's cap including carryover (e.g., $130 mil for the Packers this season including the $7 mil carryover). Further, if the Packers $130 mil is used to calculate the 89%, is the $130 mil reduced to the extent not all of it is used.
I sent an email to Seifert at ESPN suggesting he do a blog topic on this. If anybody wants to sent these to one our beat writers, feel free.