Default 2024 PC-12 NGX - What are these symbols?

Believe it or not, I’ve just started flying the PC12 in MSFS 2024 and I have some questions.

First, where do I find super technical details of the avionics?

In the mean time, can somebody please explain what these three items are in the PFD? I’m crusing at FL280, but those 3 items are there from very early in the flight…maybe when I enable A/P?

Oh, another question: I set my cruise altitude and FLC via VNAV to that flight level. Once I reach it, the mach number changes to .330. Oddly, it stays there until I decrease the autopilot altitude down to decision height (or at least lower than cruising altitude). Once I decrease that altitude, the mach number changes to .470. Why does it wait until I lower the set altitude before setting a higher speed?

Thanks!

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