Main question
Is 0BSD actually a valid license for work in the public domain? Would it cause problems in some jurisdictions? Is there a better option to publish US-public-domain uncopyrightable code so that people can just use it?
Background
I work for the U.S. Government and sometimes develop software that I want to release open-source. This is totally allowed by my employer and even mildly encouraged.
The crucial question is, which license should I use? My goal is simple: allow the greatest number of others to be able to use my code, with the least amount of hassle.
The complication comes because U.S. Government work product is not copyrightable as it is in the public domain. In the past I have used the Unlicense as a kind of beefed-up public domain declaration. But since then I have learned that there are various problems with public-domain declarations and the Unlicense in particular. In summary, public domain only applies in the U.S. and doesn't even make sense in other countries such as Germany, and (as a result) some companies have a blanket policy to not use code released under Unlicense or WTFPL.
I recently discovered the 0BSD license, which is considered "public-domain equivalent", is allowed by companies such as Google, and (unlike CC0) is listed by the Open Source Initiative. Note that the 0BSD text linked here does not include any copyright statement.
Additional reading
The helpful reader may be tempted to suggest I ask my employer what to do. If you are familiar with government work, you should not be surprised to discover that (1) there is an extensive document and even an FAQ which both fail to answer my question, and (2) my local agency was unable to provide any further clarification and was annoyed that I asked.