“I asked nicely and they still exploded.”
The please didn’t matter. For some ADHD teens a direct request is the trigger, whatever the tone. Teachers who work with ADHD students see it every day: a direct demand, and the no arrives before the thought does. A command, however kind, feels like autonomy being taken, and they push back before the niceness registers.
So stop sending commands. Send information instead, and let the expectation stand exactly where it always was. You are not softening the ask; you are changing its shape so it can get through the door.