Where did the leadership, or the leverage, for this come from?

I guess it was just the way the project was set up. The political machinations in later jobs amazed and disappointed me.

Did the client recognise that this was necessary?

We were doing development work in Canada in order to get a tax break on the investment. The product development work was being done for a company in California; after about 15 months on the job, we were all offered transfers down there.

Was it the something negotiated by the software development team?

Nope. And *I* was the software development team, in charge of both the 6809-based controller, and the PC-based user interface. Ridiculous, I know -- I was too ill-informed to know that what I was doing was impossible, so I just went ahead and did it anyway.