the basic contract is...

You(MJ) do the steering, I'll do the engines....

MJ is great where you have a fairly typical staging, however trying to cater to every possible design / corner case is likely to turn the code into spaghetti !

The idea would be where you have a more advanced design, the designer is the best person to be operating engines in their intended sequence / modes of operation

this would be okay where there are nodes but is going to be problematic on modes like landing ....

You can already turn off autostaging. And you can control engines via action groups. I'm not sure what the feature here is.

Ah, 2013, yeah this is likely fixed.