Playing with http://floxdev.com (thx @grhmc for approval) found via @a_hoverbear . Really slick experience on the top of the Nix. Awesome to see BEAM support out of the box. Would be nice to have some ENV to turn on progress indicators instead of hanging for dep downloads.
Have not found a way how to tune the policies (e.g. having midnight GMT on every machine may not be what you want). Small tweak for the (excellent) doc -- the created channel will be "stable" not "master" as used for jobset uri and package name.