In some places infrastructure is managed by chef, puppet, ansible etc that can setup a single user for deployment purposes on the target machines (ssh etc).
Spaces enable great isolation but also a lot of duplication, especially where infrastructure is concerned. I understand the need to have separate machines and accounts however I think it would be especially useful if we could have global accounts that can be used by any space when setting up their deployment targets. Even better would be the ability to limit these accounts to specific spaces if required.
This would allow global accounts to be managed centrally while also allowing space specific accounts if necessary.
You could take the view that this poses a security risk but it’s really no different to having all deployments in the default space, except that the deployments can step over each other’s feet with regards to lifetimes, retention policies and the like. The security is there for those that require it even with global accounts but the ease of use is there for everyone else.