Not to this degree, but I would certainly draw the line of assistance if he gets violent or threatening. Someone that is rapidly at that stage toward a close friend is not in a mental state that is salvageable unless you have experience or are a mental health professional. I would personally begin to move possessions of value (sentimental or otherwise) to a safe place like a storage locker, away from any outbursts and look to find an alternative place of residence if things get worse. Probably not the interventionist kind of answer you want to hear, but your priority should be protecting yourself.
Hot (and perhaps tangental) take here, but I can't understand why companies that attempt to enforce these policies for security reasons, do not just mitigate their largest attack vector and move to macOS for their endpoints where possible. Far more reliable in terms of stability and security, and dramatically less patch management required for macOS clients. I'd argue a more productive user experience also, instead of fighting the advertising, new AI integrations, Candy Crush and layout changes that Windows generously provides every 30 days. Hardware is also pretty easy to resell, AppleCare covers replacements and the fleet can be pretty uniform with stock available anywhere if needed. Keep incompatible apps that are required in a Citrix Workspace or equivalent for isolation. This doesn't address social engineering or file leaks due to malicious employees obviously.