600 seconds is 10 minutes. When this happens transaction takes longer.
You should use 150 - 2 1/2 minutes.
Why have pool? Cancel pool and everyone can solo mine and get blocks.
Maybe You not understand, the rule is:
1) within 600 seconds if the network did not dig a block, will use the old rules.
This means that if there is enough miners, Two minutes will accept a block.
At now, as you can see, Mine pool no advantage.
Yes i do understand.
You are waiting 10 minutes and if no block, use old rule.
10 minutes is too long.