All fine and great with Tailscale until you company places an iOS restriction on external VPNs and your work phone is also your primary phone :(
Though just blocking particular ports for this purpose is very 90s and obviously ineffective, as you demonstrated. Anybody proficient in installing wireguard also knows how to change ports.
That's the flaw right there. Don't mix company assets with pricate use. Phone, laptop, car. Your life is already very dependent on your employer (through income), don't get yourself locked in even more by depending on them for personal tech. Plus it's a security risk to your company.
Unless you have a low paying job, which rarely anybody on HN does, you can afford your own phone and laptop. And IT won't find your messages to girlfriend or pictures you don't want others to see or browsing history.