When I was a PM, I was brutally honest about my heuristics, thinking, and product vision and made sure to give as much visibility as I could to ICs without overstepping executive leadership mandates.

And if an engineer thought I was talking shit, I'd give them the option to lead low risk customer calls with me shadowing and their manager's permission so they can see the tradeoffs a business deals with on a daily basis. Either they could prove their mettle (and I'd mentor them to climb up the engineering or PM ladder) or they'd shut up once faced with the kinds of day to day tradeoffs and responsibilities comes from being a PM for an 8-9 figure product line.

Of course, I always demanded full visibility into our hiring pipeline across functions because a bad hire is an expensive mistake that can kill an entire product line.

Also, this was how I became a Sales Engineer and later Product Manager as a SWE. I told a VP Sales and Director of Product that they were talking out of their ass but I had a great engineering reputation internally, so they brought me in on a similar gambit. My leadership were old school Silicon Valley (they lived first hand during the Halt and Catch Fire era), but this kind of culture is still common here in the Bay.

Edit: oh damn, we got Silicon Valley history makers here :0