There wasn't much of any lifting besides detecting itself as big endian support is in eduke32 for quite some time. The only missing endian related thing is XM music playback in libxmp-lite which is used for Ion Fury. For regular Duke3D, flac files can be used - http://sc55.duke4.net/ (works also with Crispy Doom).

http://korni.ppa.pl/temp/eduke32_20190829-8064.lha.xz

Duke Nukem 3D seems to work "ok" with it, though with ion fury it's horribly slow and unstable.