D&D 5E (2024) So the Armorer still need be Wearing before Don his armor.

[Clint_L]

Imagine they struck a pose and politely waited the full donning time.

To be funny, I've literally had players wake up during a night attack and say "I put on my armor!", and I have to explain to them how long that will take.

I too have had that happen. The whole fun of an attack when the party is unprepared is that they have to come up with ways to compensate.