After I saw third-party "10 year battery enclosure" offerings for AirTags, was wondering when other workaround customizations like this might appear.
Other impactful variants might be:
* senses whether another 'sibling' AirTag is present, if so, stays off. If not, waits X hours & then turns on.
* has its own motion sensor; only after X minutes of being stationary, it waits Y hours to turn on briefly
* has its own clock & (original-user-known) randomization seed; turns on at pseudorandom intervals the original user can predict
* low-power/low-bandwidth receivers so cheap & tiny now: could wait for national or even global unit-specific 'wake' request - perhaps even with parameters for duration/intervals – before powering-on AirTag portion