https://jhalderm.com/pub/papers/interception-ndss17.pdf
How do you fix this when you're naught but a humble employee? Well, a friend of mine worked at a fairly large tech company where a salesguy for these boxes had convinced the CTO they had to have them. Every tech-person "on the floor" hated the idea, so before the boxes were installed they conspired on their free time to write some scripts that ran lots of legitimate HTTPS traffic, effectively DDOSing the boxes and bringing the company's internet to a crawl for the day, like Google would take ten seconds to open. Then obviously everyone (including the non-tech people) started calling the IT helpdesk complaining that the internet was broken. MITM box salesguy then had to come up with a revised solution, costing 20x more than his first offer, and that was the end of that.
If you already are suffering under MITM boxes, a similar strategy with a slow ramp-up in traffic might work.
