MANFAN
Unlikely. T1 and T3 security areas, aside from not really being that close to each other, are on different floors. If I recall correctly, the other side of the wall from T3 security is the airline lounges so you're talking pretty major upheaval to get anything workable. You also have to consider getting passengers all the way back there in the first place. It sounds like it'd be a significant capital investment that MAG are unlikely to want to commit to considering that T1 didn't feature in their long-term plans, pre-pandemic at least.