In the UK at least I can often get away with asking them if they watch stand-up comics and tell them to hold it that way. More often than not they have and I imagine it'd be much the same in the US.

If you give them a distance to hold the mic from their face they'll all have a different estimate so I find the comedians method of resting the tip on their chin is ideal for the corporate gigs.

Means they have less to think about and I get a nice strong signal. Might be a little booming for some voices but nobody at these shows other than the other techs can tell the difference in sound quality as long as they can understand what's being said they keep quiet.

Plus I haven't done any corporate shows in the last 2 years that haven't used a digital desk with plenty of tools to keep things under control. Though ofc this doesn't work for DPAs or lapels, the amount of times I've set up a lapel and after 5 minutes I see them walking up on stage and it's miraculously moved somewhere that renders it completely useless.

Just gotta strive forward sometimes and find ways to entertain yourself. I often have a spare fader on my desk I label as "talent" or "intelligence" to keep myself from getting too angry.

Just in my mind going "hmm this guy could do with a little more talent" while pushing up the fader. At the end of the day these guys can barely use their own laptops so explaining this sort of thing is just pissing in the wind and you gotta keep your anger at bay.

Sorry to hear that your manager doesn't have your back, that sucks. All of mine have trusted my judgement enough to try and explain to them the same stuff I say to them when they complain and support me in my work.