You shouldn't be switching from
this board (and sub-boards) to get the best answers regarding mining. I've recently received a lot of counter-answers to your conclusion; generally speaking, it should work with a single miner. Sources:
(1),
(2)Regarding historical statistics: Pools also provide statistics derived from the records of the all miners who joined them. If their database is as it usually is, your historical statistics won't be reset. Once you split some of your hashrate to another pool, the first pool may only see your hashrate drop, not your statistics starting from zero. cmiiw