Those minelab graphs are a good general idea but you'll learn a lot more with trial in the field. And that doesnt mean hours and hours and huge holes, just get the biggest bit of lead you've found plus a few of other sizes, .22 bullet, big shotgun pellet etc and bury them then switch between the timings and that's the best way to learn.
I have a 4500 so no fine gold but my understanding is it like an improved enhanced timing and shouldnt go deeper than Sens extra, unless the ground is too noisy for sens extra, but that would be talking about mono coils id guess, this should be the advantage of the dd, allowing you to run deeper timings than fine gold without the extra noise.
All my testing has found that sens extra is a very deep timing but its advantage on sub gram gold is huge over normal timing. Sens extra does sound off a lot louder on hot rocks though.
Normal might still go deeper but it gives a lot more ground noise and loses out on the smaller stuff you're more likely to find along the way.
It's all trial and error but I'd really go with sens extra and the rest like gain and stab is up to the conditions on the day.