Here's both cases that I tried, the only circumstances that seemed appropriate, and neither worked:

mob
Logout()
usr.client.macro_mode = 0
..()

The Logout() version above gave a null error that the client is null. So, I tried to define it in client.Del() instead, to ensure that the client is available while disabling macro mode.

client
Del()
src.macro_mode = 0
..()

But that didn't work either. I'm at a loss. I can always disable it manually by clicking on the ALT button afterwards, but it is quite a pain.