Yesterday I entered through Mexico Int'l Airport. No more forms to fill out. Use only your passport. They stamped it and entered manually the visa expiration date. They gave me 180 days asking only the purpose of my visit and where I was staying. I did show a reservation to exit in 3 months on January 18.
After scanning my passport, the agent asked if it was my first trip to Mexico. They apparently don't have entry and exit information on the screen. That is consistent with my experience overstaying my visa by 3 months a few years ago. Thee were no consequences in later entries.
The immigration system remains primitive.