The fact that chewitt didn't know what he was talking about regarding Dreambox has been clear from the beginning when he didn't even know that LibreELEC images don't work on this device no matter how much he insists on sending people to read info about things he hasn't even tested with a Dreambox. My question was directed to @emanuel.
The silence of _emanuel_ is enlightening, if he has not said anything about it is because he knows that there are all those problems in LibreELEC that you mention but he has no way to solve them.
If those who have a Dreambox and have tried LibreELEC haven't noticed all this up to this point is because they have simply only run 1080p videos max, haven't enabled Expert mode to see that in some versions there is no passthrough and haven't tried to change the language or play a 3D SBS or HOU video. LibreELEC this way is completely useless. Of course this is not solved by blaming others for trying solutions before asking.