Re: German dubs. Short story: No adjustment is necessary.
I hoped so and muxed the file with 4K83. But while it seamlessly syncs with ROTJ DE 2.5 there is is a noticeable asynchronicity in 4K83. It’s for example quite obvious in the scene where Leia tells Han that Luke is her brother. But if you are sure that there shouldn’t be a noticeable delay, then maybe I should just try it again.