He's moving out of state

I just got him to deliver a signed (modified) separation agreement, and find today that he’s moving out of state.

I think the intent is to prolong the process… it’'s been well over a year.

He has been homeless since around October of last year, and living in his car. I’ve had no way to serve him until last week, when he gave me his work address. But the day after tomorrow he’s hopping in his car and driving back “home” to Kansas.

Do I still simply file here, and have him served in Kansas? I have his parents’ address, but I’m not sure that’s where he’ll be staying.

Yes, you file here and serve him in Kansas.

And the separation agreement (notarized in Wake Co.) will still be legally binding, yes?

Yes absolutely.