That's the first time I've heard anyone suggest Trump's private office and storeroom at Mar-a-Lago, where the classified documents were found, was a SCIF.
No one expects anyone to be aware of everything, so it's understandable that you might have missed it. Every President's vacation home since JFK has had a SCIF installed. Any place a president routinely handles or discusses classified material has a SCIF, either long term or temporary.
The existence of the Mar-a-Lago SCIF is mentioned on the Mar-a-Lago Wikipedia page. It also made headlines after the media had one of their typical meltdowns after creating a narrative based on little information and copious amounts of assumption, as outlined
in this news piece of the time.
Stories regarding security clearances and SCIFs get my attention because I still have my Top Secret / SCI security clearance,which I've had since the Oklahoma City bombing in 1995. I had a cousin who was the head guy in charge of the federal emergency response and recovery for terrorism and disasters. He gave them my name as someone who knows about hard drive recovery. I started with a conditional Confidential clearance and by the time the background investigation was completed I was bumped up. I've had my background renewed every 5 years since.
I was plug-n-play ready to go, and was taken to the Pentagon 3 days after 9/11 where I worked, ate, slept and went to the bathroom inside a SCIF while I did hard drive recovery. There were several of us in there, each with a different SCI. The "C" is for "compartmented." Meaning, compartments are necessarily separated from each other with respect to knowledge and organization, so that someone with access to one compartment will usually not have access to another. I knew the information that I recovered, but I had no idea what information the others recovered. We didn't compare notes.
We were essentially locked inside the SCIF for nearly a month all the while under a palpable sense of urgency that only increased day by day. Finally, on our last day, we gathered up all our belongings and were taken to the White House where we were personally thanked by President Junior Bush, we ateva great meal, and we were taken to our homes around the country by military transport.
The next day we invaded Afghanistan. Then I understood the urgency.
I have been in four different SCIFs.
No way are the storeroom and desk drawer SCIFs.
Classified documents aren't stored in a SCIF. They are stored in a secure, authorized location. They are handled, read and discussed in a SCIF. Trump's office, including his desk and all of the desk's constituent drawers was a SCIF. The storeroom (the FBI called it a closet) may or may not have been right off the office. If the storeroom was JFK's bunker (that was oft reported as a basement) would be an authorized, secure location. In any case, the Secret Service provides an additional security layer will beyond that of a locked garage.
The Mar-a-Lago SCIF would have been operational whenever Trump was at the residence. It's function as a SCIF would have ended as soon as he left office (which is why he didn't scream SCIF) and would have been dismantled (white noise generators, Faraday Cage, electronic jammers, a whole host of other things) about 6 months after the end of his presidency. But some things may have been left there in case he becomes again. If he doesn't become president again, any remaining items would be removed.