Yes, I’m sorry, if my original response looked like brand new proposal: it’s rather a suggestion to the original one.
Yes, the proxy group is very similar to your original propose. What it, however, doesn’t try to address is the multi-homing (that I see more fitting to the proposed proxy profiles).
If we remove the attempt to address the multi-homing at once with this, we can limit the proxy to belong to either zero (the standalone proxy, as we know it now, that would be assigned to the host) or exactly one group (in this case, the proxy could not be assigned directly, but instead the group would be used).
The group should have a possibility to provide a hostname the hosts should prefer for reaching the proxies in the group.
However, the group itself would not try to address the multi-homing scenario, and the proposed Proxy Profile could address this case instead.
The nice thing about this is we don’t need to rollout both concepts at once: we can focus at the proxy groups now (without multi-homing), and then think more about the profile concept.