Some more nerdy talk / discovery:
Keeping you batch size consistent is more efficient than fluctuating it; e.g. 3-3-3-3 is better than 2-4-2-4
Bigger batch sizes also gives you more economy in the long run. However in the stort term small batch sizes / no batch is better. What would be interesting is a formula that tells you what batch size you should use if you want to have the most resources after x minutes, e.g. to determine what batch size is optimal to do a 6-minute attack.