I don’t think that’s possible if they don’t have a working boot drive.

Oh I see now. You should be able to import them. Worst case is you can’t then you’re back where you are now. There shouldn’t be any data loss.

Yeah. As far as I understand it, exporting is more of a config thing. You can shut down your system asd boot it while missing drives (done this by accident) and boot while missing, and it’ll say there’s an issue with it. Shut down, pop the drives back in and you’re good to go on boot.

You can just drop in a new boot drive and install from a usb. I do recommend setting up a boot pool mirror though. This way if one goes down, you have a spare that can be used to help recover more quickly.