Triple boot on older MacBook Pro

I want to install MacOSX 12.xx (latest version of High Sierra) + Windows 10 Pro + CentOS Linux on a MacBookPro (version 8.2, 2012). Is it possible to do this using Boot Runner? If it makes things easier I would be willing to install either Windows or CentOS on an external USB or Firewire hard drive.

If so, I would really appreciate a detailed step-by-step procedure.

Thanks

Boot Runner will set the startup the same way as the startup disk preference pane. Since Linux usually doesn’t show up there, it most likely won’t work. We are working on Boot Runner 3 and will see about improved support for triple-booting.

tim

Thank you tim for your prompt reply.

Couple clarifications: The MacBookPro is a 15", late 2011 (not 2012) model. And, I meant MacOSX 10.13.xx. I don’t think these make any difference as far as your reply is concerned.

Do you have any idea when Boot Runner 3 might be available?

Thanks