Doesn’t seem new to me, Tendermint makes use of deferred execution from day 1. For exactly the reason of being able to pipeline block execution during the voting phase. There’s been a lot of discussion from the Tendermint / Cosmos community on this front and the ramifications (i.e. downsides) of deferred execution:
Notably, deferred execution prevents gas refunds as they exist on Ethereum today.
On the topic of increasing the block gas limit, block validation rate must be much higher than production rate not for Nakamoto Consensus, but so that users can full sync. Therefore, changing the consensus protocol does not allow us to decrease this multiplier.