From what I can tell, the only way to get a checklist to show up is for it to happen automatically, based on certain criteria. That works great, but if something changes in that criteria, there's no way to manually insert a pre-populated checklist....or if someone accidentally deletes a checklist that was automatically inserted, there's no way to get it back.
Can you consider adding the ability to manually insert a checklist into a case?
As administrator, I have asked for two years, for the ability to restore a checklist that was accidentally by human error deleted. This would potentially be the same resolution for those issues as well.