Old rules FMT / FMM set your pinkie one inch into Mexico anywhere, and 72 hours later the law declared an FMM is needed. This has been the rule since I first remember, back in the 1960's.
Now, a visitor can stay SEVEN DAYS without the need of obtaining an FMM. This is a more LENIENT stance not a stricter enforcement of Article 42 migracion.
Baja California businesses wield a huge stick with state and federal gobernacion. This has always been the case. The new law was/is confusing to many people and rather than wait and hope the law did not impact tourism the business sector went on the warpath.
It has always been this way NOTHING HAS CHANGED for Baja California. But other border areas, say along the Rio Grande the 7 day rule is more lenient.
The words Mexican Government and Common Sense is a world class OXYMORON.
But if a person is a RESIDENT here it's a whole different story. Migracion comes knocking on the front door with a policia municipio on each shoulder. The offender better have a residente permanente card or a valid FMM. The migras allow the offender so much time to get squared away then they come back and check. But again, this is for extraneous residents, not tourists.