If you use the option to Promote to All environments, you lose the option to ignore unavailable targets.
Hi Ryan,
Thanks for getting in touch 
Got the dreaded words that this is by design. When we added the feature to allow you to select multiple environments at once and deploy to all some of the advanced features had to be removed when using this for convenience.
Generally, as with many things, scoping became an issue. For example. If you had a single machine in two environments, would we skip it for both. If yes that sounds like the absolutely logical answer, there would have been cases where it was only to be skipped in one environment. Designing an extended UI around it would have been much less of a convenience. The same with steps.
It was decided that just removing those features if you want a quick deployment to many environments would be better, and to customize this then deploying individually is required.
Sorry if its crappy news.
Vanessa
That’s ok - I can understand that. It will be less of an issue for us anyway once we are able to use multi-tenancy. Also it should be an exceptional case when machines are down. Thanks for the answer anyhow!