haha thanks for missing me. I've been disorganized so it's been a while until returning properly XD
I think for arc organisation, you can just put
Arc 1
-ch1
-ch2
-ch3
Arc 2
-ch4
-ch5
just a little notation when an arc changes when you post the chapters, or a note in the manga saying -end of xyz arc-
Although I think generally most mangas don't explicitly state when their arcs begin or end, you read it a lot in the fan-made wikis but not really in the manga itself.
I'll see if I can read a few more chapters soon and give you feedback :)