just a ? and maybe a sort of a heads up to kano in case it is an issue that you are not aware of..      

for the last 2 weeks I happened to notice that any time a block is found on the network and then the pool starts working on a new block. I have noticed the time it takes for the pool to start on the new work is some times as much as 5 mins behind.

for instance block number 499476 found by slushpool at 2017-12-15 13:31  and then they instantly started working on block 499477 and working on it for almost 5 mins before the time kano pool switched and started the new work on trying to work on block 499477

sometimes its only about 15-20 seconds difference that the pool takes to switch on to a new block and get to work and figured that was just normal time its taking for other pools to switch work after another pool finds a block..    But over 4 mins seems like a real long relay time.  

so incase that is longer then it should take I figured I would say something to let you know so if it is a problem you could see what the cause might be.   Tho if not then I guess its no biggie and you would know its not any thing that could cause any issue with the pool missing out on the big race to find a block before any other pool ever did.