Its a good letter but I definitely wouldnt give it to him. I think you should concentrate in making the meet as pleasant and fun as you can.
If you think you MIGHT give the letter then you will spend the time looking for signs as to whether you should and that's going to be hard on both your detachment and your PMA.
Vossy is right Put your focus on being your best self (as you want to be) and then just be.
Avoid R talks but if, and only if, he brings it up listen to what he has to say. It might be that you can offer to write a letter rather than talk about your feelings straightaway, but it would need a substantial and obvious cue before you did
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress