[Nutany]

It depends on the Instructions- whether It's left at the front door or requires a signature.

If It's the latter, then yes, you'd need to be there to accept delivery. Narrowing down the delivery window (SEing the company that you're only available for an hour or two) saves you having to wait all day.

So instead of waiting there, couldn't you just not accept the package and then go to the package station and get the package there?

It depends where It's redirected.

If (for example) It's at a post office, some require ID with your current residential address, which will obviously not match the drop address.

I think they would be tolerant enough to accept the fact that you have moved. (Most people in Germany keep their ID for the max amount of time, since the ID is really expensive, upwards to 100€, even more for people who aren't native germans)