The minimum value is 2 minutes. I can not set 1 minute. Can you check ? We need at least 1 minute to avoid mining on unprofitable algo that is volatile (tribus, skunk, timetravel).
I can't see any reason you'd want to profit-switch every 1 minute. Depending on the mining software, it can take a few minutes to ramp up to maximum hash rate. BMiner and CCminer are great examples of this. Plus most block times are longer than 1 minute. The pool doesn't have any fresh information about the statistics of that coin until the next block.
And depending on the pool's share mechanism (PPS vs PPLNT) you can actually be penalized for mining so shortly.
I've come to the same conclusions. Can't remember what the default is, but I've set the switch interval to 10 mins and the threshold to 3% Experience shows that *NOT* chasing the high price of the minute (or in this case 10 mins) and due to most of the multi/multi's being PPLNS, I stay ramped which more than makes up for chasing