As usual, we need a spin-kickstarts package build containing the kickstarts actually used to build the release.
There is one pending PR for F28 which we should clarify the state of: https://pagure.io/fedora-kickstarts/pull-request/383 . I'm cc'ing dustymabe for that purpose.
This is a release blocker, per Final criterion "A spin-kickstarts package which contains the exact kickstart files used to build the release must be present in the release repository. The included kickstarts must define the correct set of release repositories."
I don't think this is required to be in the repos, so I'm +1 0day Blocker. (The distinction being that if there is a mistake in here, we won't need to respin the release candidate).
It must be in the "release repository", which basically means it has to be in the compose, I think. (This means I was probably wrong about generic-release, now I think about it).
Accepted0Day is actually a pretty small thing, it's mostly just for really bad upgrade bugs.
OK, then I'm also fine with +1 blocker
spin-kickstarts-0.28.1-1.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-673b36b865
spin-kickstarts-0.28.1-1.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.