In my case, I forgot. After the 15 day BK ASQ hotel solitary confinement, it happens. I had a re entry permit and a current visa. When I realized the error my life had fallen into, I went to Chiang Mai IM. They did not fine me for being late. However they did NOT say it wasn't needed. They wrote up a new form, inputted info and stapled a new TM 30 slip to my passport.
They have nothing better to do, it gives their existence, meaning.