You could buy a remote KVM device. The serial port of your target box connects to that and the KVM connects to the internet. With that, you can watch the device during boot and access the console remotely.

I used to run a web hosting business and we used those. I have not shopped for a personal one, but surely there must be old and used ones for sale.

Bonus: our hosting business ran on FreeBSD so I can confirm there was no problem there. Because it’s a serial connection no OS support is required.