Even if your server does not have proper IPMI, most colo providers have an assortment of ip-kvms, you can ask for those and access your server from any modern browser.
I'm pretty suspicious of trusting the firmware on things like that either, to be honest. (Personally, I tend to use serial cables and a little custom board to turn serial breaks into resets, but I know my NIH instinct is probably a little on the high side. It would be unreasonable for me to suggest someone new to colo start making random extra boards to stick inside their machines!)
You do not need to stick it inside, it plugs into monitor and keyboard ports. Power-on and reset are usually done manually on request. And you do not need it plugged in all the time, only to reconfigure network or boot values.
That's definitely a level of remote-hands intervention I've not had from the handful of places I have racks of colo kit. You're right, it might be something some of them do for other customers though; I've never really asked. They'll certainly push a reset button, swap a drive or rack a server that's shipped to them. (Though hardware's reliable enough nowadays and I have go to data centres so rarely that it's a bit of a fun novelty, and I like doing it myself.)
I've been colo'ing forever. I'd consider a Lantronix spider ipkvm available on request to be like minimum viable colo service. It's usually up in 5 minutes when I submit a ticket to the NOC.
I bet your provider has something like that. It's a godsend when you screw up, say, the hypervisor running state somehow and need bare metal access to unbork it :)
My version of this is to use a serial console server for direct access, rather than vga + keyboard. If the kernel is still running fine but network access is down, I have a getty running on the serial port. If the kernel has locked up too, I hit the reset button by sending a 500ms+ serial break (special circuit, highly recommended) and the bios has serial redirect, so I can do stuff like hit del to drop into bios setup or uefi shell at that point.
But I expect you're probably right some or all of the providers we use do have something like that, as I speculated in the previous post. I've just never understood the point of vga-type stuff when bios/uefi serial redirect exists and serial console is more convenient anyway once the kernel has started, so never asked the question.
