Thanks :-),

Regarding "Your hashrate on yiimp based pool would disappear every or so hour for few seconds to minutes. "
if it's more then few sec please check the stratum diff the miner is on, maybe it's working on high diff for few min or while working on high diff for few min the dev time comes and it's switches to dev pool and so you get the miner disappear for few min.

Hope it explains it :-).