I implore anyone who works in government to hang on as long as possible. While it might work as a protest in the short term, in the long term, you will be backfilled by Trump Loyalists.
The best form of protest from inside the bureaucracy is Work-To-Rule.
These sorts of resignations are to be more and more expected as Trump purges the Bureaucracy. He’ll have to do that first before he can get a loyal government that will go far beyond what any of us think in terms of evil.