It's certainly possible, but I don't think it's supported. I'm not just talking about hardware issues, but like general support. As far as I know, if you have a mac under warranty/applecare you can book an appointment with a 'genius' to help you with any sort issue, hardware, software, or even just general instruction on how to do stuff.
I would guess that if you showed up with a mac under warranty but with a custom OS installed, they would boot macos in some fashion and run whatever their diagnostic tool is, and if the hardware checks out they'll tell you to buzz off.
I guess my point overall is that Apple seems to be pretty intent on curating and supporting a specific user experience with their products (which is a big part of their pre-occupation with controlling everything top to bottom in the first place), and supporting 3rd party OS's seemed at odds with that.
