EH, The old saying "when in doubt, do nothing" would apply to your situation. Since you are still not sure what to do, then sit quietly, the answers will come. EH, when the time is right, you will know what to do.
You do realize that you can turn the tables? If you wanted to try something different, the next time he asks about getting together, you could ask him why he wants to meet. You could ask him if it's in reference to the children, if not then don't do it. You are the distancer and he is the pursuer...you are a challenge to him and he wants to have that connection w/you again.
I'm glad he came to get the children and spent a wonderful time w/them. The memories of spending time w/his children will stay w/him. As to whether or not he does it again that is the $100 question. Sounds like he had some clarity during his time w/his children.
I hope you are doing well (otherwise).
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.