When did Mark Waid chip in?
JMS made it clear that he did OMD as a favor-to-a-friend to Quesada and that the entire concept was EIC's and not his.
"Often times when you care a lot about something, you can disagree strenuously. Personally, I was perfectly happy keeping them married; I didn’t think Mephisto should be used in that fashion, and I didn’t like the idea of erasing everyone’s memory. Whenever you bring magic into a story you have to be really rigorous about the rest of it. And a lot of logical questions to my mind were not being addressed. Having said that, it’s a complicated universe and it is Joe’s purview. Yes, we disagreed strenuously, and some of it leaked out. I take responsibility for that, but the reality is that Joe I consider to be a friend, and anyone who wants to say a bad word about Joe has to go through me first."
— J. Michael Straczynski (
https://www.amc.com/talk/2008/05/masters-of-scif-1)
It definitely seems like the concept of OMD was something Quesada (no writer) borrowed from Superman 2000 (
https://sites.google.com/site/deepsp...-2000-proposal) which was co-written by Waid, Morrison, Millar. Grant Morrison in interviews implied that Waid was more keen on ending superhero marriages than he was. So I think Waid was the secret architect of the project.
Not according to how JMS wanted to do it. JMS wanted to alter events so that Gwen and Harry survived, but most of the events in Spider-Man continuity between then and now happened. He said that he was in the middle of the working on the timeline didn't get far when it went public and caused a ruckus.
Personally, I think if Gwen came back then OMD would have gone better. For one thing the Lee-Romita era is inherently charismatic as a setting, whereas the Bronze Age from Wein-Wolfman-O'Neill era (which is what BND amounts to) isn't charismatic in the least.
OMD wasn't put together until 2004-2005. By which point JMS was there for 4 years.
And it's pretty obvious JMS was never on board with it, since there's no foreshadowing or buildup to OMD in his pages. I have read his run from beginning to end and there's no sense anywhere that this is where it was leading up to. BACK IN BLACK is JMS' own finale of his run.