Wouldn't it also still be doubling what is added to the blockchain in new blocks, instead of 2mb every 10 min you have 1 mb every 5 min for a total, still, of 2mb every 10 minutes, and still be adding the same, if not more, data transmission between nodes that is the bandwidth concern..
the 10min rule is an average of a indirect rule.... not a direct rule in itself
some blocks can take an hour+ some can take <2minutes.
changing the difficulty and rewards and halvings and everything else still does not guarantee a 5min expectation.. only an average
this may still be <2min-1hour+. but a higher majority happening in a shorter period.
while screwing with so many bitcoin features that should not be touched.
pools already have issues filling blocks with new tx's if a block is solved in 2 minutes, causing empty blocks.. while its checking the last block. so this 'empty block' result will occur more often
thus its not actually helping to get more transactions confirmed longterm. infact it can make less transactions get confirmed