Sceptical is good, we all win when we respectfully challenge each other's position's.
I near as I can tell, I think your questions were all answered in my previous posts.
I agree, it could be quite complicated, if you allow it to be.

In a nut-shell, Sony makes a warning that the project is too large, but allows creation of the too-big project anyway, try it. If you have the space, preparing your project will be allowed, regardless of size and the burning equipment on your computer.

Nero allows for burning DL size projects, and it sets the layer break.
Nero designed their software to accomplish this.
I have read of others success when using Nero to burn DL (on other forum's) , but have not made a DL burn yet - as I clearly stated in an earlier post.
Nero has implemented two technologies to support doing this:
LayerMagic™, and SmoothPlay™ (some of the information on that linked page is for Authoring with Nero, which is not a requirement)
I don't claim to understand all that Ahead is doing with DL, I will learn more as I go - and I have read of some less-than-perfect glitches with people using Nero, but also some success too.

BTW, referencing a previous post in this thread.
Pinnacle announced that DL was supported in Studio 9 Plus, and 9.3.*
I have tried to create a project > SL size, and they do not support DL yet, even thought they claim to currently support it.

Sony enables it, even though they say it is not supported yet.
I'll take unexpected benefits over vaporware any day.

Good luck.
Chris

Thank you Chris. I will give it a shot in the near future and post back.

"I rarely burn with DVDA anyway - Preparing with DVDA, and burning with Nero is my workflow, so if DVDA 'officially' supports Double layer is of little consequence to me, I already have it."

I agree 100%, aside from in-program burning the only other difference may be the warning message.

Thanks Again

Any progress on this issue yet - it's a nuisance

If they do anything it will be the following, based upon past experience. They will incorporate it into DVDA 3.0 and you won't be able to buy it unless you also buy Vegas 6.0. I begged them to sell DVDA 2 as a stand alone last time and they would not do it. It is strictly a marketing issue. That is why I am still using Vegas 4 and DVDA 1.0. They work just fine.

John