Your theory might explain the root cause of this annoying issue, lol ... It totally makes sense (if drug pack falls on void undermap it will probably be gone - assuming the engine doesn't respawn it in the same way as when the player falls undermap).
I'll add your code chunk to my source code, recompile and do some testings ...
I'd also like to take the opportunity to ask if you guys know a way to make the SCO load the latest save game slot after calling TERMINATE_THIS_SCRIPT() function (I had to do some workarounds to make a similar thing on V1.1 - Player gets teleported to the latest location, but without guns and sometimes the clothes are changed - ugly workaround tbh :/ )
If I can't find a way to add this feature on next version, I'll probably end up changing the player model to Niko Bellic (just like in HuN's Gang Wars mod).