Dynamically Controlled Bitcoin Block Size Max Cap

Regarding... i. http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010493.html ii. http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010499.html

Could we please keep the conversation specific to the proposal presented at http://upalc.com/maxblocksize.php ? If you find any demerits to this, please point them out. Otherwise, I'll ask for a BIP. The proposal in algorithmic format is as follows...

If more than 50% of block's size, found in the first 2000 of the last
difficulty period, is more than 90% MaxBlockSize
         Double MaxBlockSize
Else if more than 90% of block's size, found in the first 2000 of the
last difficulty period, is less than 50% MaxBlockSize
         Half MaxBlockSize
Else
         Keep the same MaxBlockSize