We're currently in the midst of 51 ongoing "national emergencies" [1], dating back to at least Carter. I think something that the next great empire will learn from is to limit emergency powers as well as the ability to create emergency powers, because in spite of their name they inevitably end up becoming normalized and just used as regular powers.
The description of some of those emergencies is comedic: "Declared a bank holiday from March 6 through March 9, 1933, using the Trading with the Enemy Act of 1917 as a legal basis."
[1] - https://en.wikipedia.org/wiki/List_of_national_emergencies_i...
This has been unfortunatelly an issue at least since Caesar times. :P
Most of these seem at least plausible to me given they almost all have to do with foreign conflicts, and given that they have to be renewed every year, they can't be too excessive since Trump has kept in place 8/9 of Biden's emergency declarations? and your description of the most comedic one was actually maybe the most important one?
It was to stave off a bank run at the beginning of the great depression, and it was only done as a temporary measure so that Congress had time to write the long term legislation which they did 4 days later on March 9th.