If a block takes too long to find, diff. will automatically drop on next drop. If you look at the previous sequences I posted, the 30min. or more case will yield the following :

120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-120-1800 = 2.93 mn block average

Which is way above the 10% limit, triggering a diff. drop on next block.

What I'm gonna do this time is extract actual block times from the NRB chain, and use those as test cases for the new diff. algo, so we'll have concrete data to monitor the suggested change's impact on difficulty.