There are no rules around that, the only rules that apply are line of sight and the ability to control it the entire time. Technically, even parking by drone as

There are no rules around that, the only rules that apply are line of sight and the ability to control it the entire time. Technically, even parking by drone assist technology, where the drone itself can go back to the launch spot and start lowering itself to the ground requires you to be in control and able to abort. I was in a situation where even though I specified a return altitude of 50ft, the drone went straight instead when parking, which would have caused it to crash in a tree. In other words, the pilot needs to be able to control it at all times, but does not explicitly have to actively control it at all times. Who knows how long specific language around passive/active assist requirements are baked in.