Tom said: "It sounds like a nice piece of work, but our worry is we may simply not be able to add this feature with enough capability/testing to address your desired use cases in the timescale we anticipate you need this in. That said we are ready to work on this right now so hopefully we can make an effective solution in the time available."
Let's all remember that we have a "baking in the community first" mantra here, and for critical (read complex) pieces of code like this, I definitely want to see that baking taken into consideration. So let's be sure to factor that in too!