i like the idea of the alias, it would give a way to avoid ever getting the "always" checker and to determine from the container if we have the real publish workflow activated.
why would you load the "always" checker even when pwfc is activated? i don't think people will want to use it explicitly, or do you? 

always loading both is not possible: pwfc relativly expensive to load and it has a security voter that hooks into symfony security. so i think the configuration option should really control whether to load pwfc or not.

i propose we make the pwfc service name a configuration option defaulting to the default pwfc and create the alias based on that, resp. create the alias to the "always" pwfc if workflow is disabled.