Thanks for the advice PSIG.
It's how I ended up tuning a couple of NA+t engines on ms, but the issue for me is that the initial ignition table is a stab in the dark.
I feel like if I have a stock ignition table to start from, I'll just pull 5 degrees in positive MAP and start from there. I can be confident that under 100 kpa the engine should feel more or less like it did NA (if using speed density).
Equally, there's a good chance you can add a few degrees under vacuum anyway as stock numbers can be conservative.
That is a LOT of time saved on the butt-dyno and a lot of guesswork confirmed from the start.
And for fuelling, well that would mostly be over-written anyway if adding a turbo, but still useful if making small modifications to an NA engine, the relative change in injector pw over the load/rpm graph will give you a lot of information you wouldn't otherwise have, and you can quickly replicate those into TS against what was auto-generated.
From what you guys are saying, it sounds like you think it wouldn't be very useful - I take your points