Are Airtags or SmartTags allowed in the suitcase?
Basically, baggage trackers are portable electronic devices and are subject to the International Civil Aviation Organization's dangerous goods regulations for transport on aircraft. Therefore, like cell phones, laptops and tablets, they must be deactivated in checked baggage during the flight because they have a transmitting function. However, airtags can only be deactivated if the battery is removed. However, an airtag without a function is also no good as a tracking device for the piece of luggage.
However, Lufthansa, for example, has lifted the restriction on airtags in consultation with the German Federal Aviation Authority. It is assumed that the devices do not pose a potential security risk. Provided that the battery installed in the device does not exceed a lithium content of 0.3g and the battery does not deliver more than 2.7Wh. This is true for airtags. So YES, airtags are allowed on Lufthansa flights. There is also no corresponding ban at the airports.
The situation is clear for Lufthansa, what about other airlines? Each airline has its own regulations on the subject and some have probably not yet caught up with Lufthansa or other major airlines or have not yet published a corresponding guideline because the subject is relatively new. If you want to be on the safe side, check with the airline and their regulations before you fly, but it is possible that you will not find a statement on this topic yet. Unlike medications in hand luggage, airtags are electronic devices and therefore completely different safety regulations apply here.