Amen brothers, amen.
It would be great to have a improved ME released with BS. If they work on it while working on BS they can find bugs/glitches/probs that may come up with each beta version and then correct them before getting so far ahead in one area that it would be more costly to go back and do it all over again.
If they wait til after, what's the point? The sim plays and money is made, then ED is off to the next project. I'm not saying they won't fix bugs that affect playability (1.12a show that they will), but what would be the motivation to fix the ME at that point?