User-Provisioned Arbiter Node

[necouchman]

Version 4.20 introduced the ability to create a two-node cluster with a local arbiter node. The instructions only seem to cover how to enable this functionality for Installer-Provisioned Infrastructure - I'm wondering how this is to be accomplished with user-provisioned infrastructure?

If I try to run the installer to create the manifest file with the platform set to none, I get an error:
arbiter.platform: Unsupported value: "none": supported values: "baremetal".

If I try to configure the arbiter with a different platform, I get an error for that, too:
[arbiter.platform: Unsupported value: "none": supported values: "baremetal", arbiter.platform.baremetal: Invalid value: {}: cannot specify "baremetal" for machine pool when cluster is using "none"].

And, if I move the overall platform to baremetal, then I have to fill in all of the expected values for installer-provisioned infrastructure - VIPs, boot MAC addresses, etc.

Any way to make this happen?