... when ships without jump engines arrive they join the task group and the jump escort ship performs the jump, after which the other ships leave the task group...
One of the best anti-micromanagement things steve has done is set it up so the the jump ship can just sit at the JP and whenever a ship without a jump drive has a transit order at that JP it will allow the execution of the tranist order.
You do not have to make the tranisting fleet join the jump ship fleet or vice versa.
It even works if the jump ships is on either side of the JP.
Its drawback is that it seems that the jump ship must start time interval at the JP for it to work. I'm ok with this and if I want my jumps moore coordinated i just use a smaller time interval. Usually its not that important.