To do cue support correctly it needs the input plug-ins to know how to handle things & yes old 2.x era plug-ins have faked it to an extent as well as cue player 0.57c but they then rely upon specific input plug-in versions which means they struggle to use the newer revisions of the input plug-ins under WACUP.
Of the main input plug-ins, in_mp3 is the one that still needs to be replaced but that handles a lot more than just mp3 playback (e.g. a lot of the streaming support goes through it).
So once I've got an in_mp3 replacement then I can proactively look into native cue support. As unless you can seek immediately to the point needed without hearing part of the starting audio (as the existing solutions often experience) as well as knowing about continuous play through then it's not going to be right compared to other players & what's expected with decent cue support imho.
-dro
p.s. 3 posts about it isn't going to help move it up my todo list when my immediate focus is dropping the need for the use of the 5.666 core which will then make it easier for me to make bigger changes without being held back as is the case currently. I get that it's an important feature (my attempt to crowd fund a better solution in 2010 shows I know this but no one back then wanted to stump up the cash so I could spend the time to do it).