Oh that I happen to know something about - you’re making stuff up. I’ve got NFPA 72 right here if you want to point out where this alleged requirement for “multi-sensor” detector exists.
In fact there are specific requirements to use only single sensor type alarms - such as near cooking equipment.
You can go the the NFPA website though where the publicly facing website notes they are “recommended”. They are not and have never been required.
