Hi, There are a few new bugs related to this, perhaps because it's common practice in game packages, that split <package> and <package>-data, and move all the doc to <package>-data.
I ended here reading: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=857974#15 "That is broken by design: #766711" though apparently this is more a problem of implementation rather than a design issue. I see that DH now generates an error with compat=10, but the documentation doesn't hint at this issue. Also AFAICS the current binNMU changelogs created with such a configuration are lost (the binary package just contain the <package> -> <package>-data symlink and no changelog.<arch>). This looks like the main/only issue to me. Would you provide a status update? (are changes/clarifications planned?) Cheers! Sylvain