I've been around when organizations have had acting directors, and they are usually stuck in neutral, not wanting to step out in any one direction, waiting for new leadership to arrive. In the military, we called them "Horse Holders." Standing there, holding the reins, waiting for the next rider to mount and lead the charge. Not much is getting done in those agencies. No one is certainly taking risks or setting direction for the organization.
All of the lack of permanent (as permanent as it can be in the current administration) leaders is well laid out in this Politico article, Trump Broke the Agencies That Were Supposed To Stop the Covid-19 Epidemic.
I'm betting that easily half of emergency managers could not name the Secretary of Homeland Security.