I just always assumed timing would be an issue from the start because of cpu variance, so I opted from the beginning to just have multiple versions of loopable tracks instead of relying on mixing in-engine.
it's actually not hard to do at all... the capability is there. it would most likely be a minor change to have the audio sync. I just don't think the devs working on Chromium quite understand why it's important. In fact, I don't think many people period understand why it's important.
A composer and create a 2 minute track, export it out into 4 parts. In-game you can dynamically change the mix and can create an adaptive audio system that reacts to game triggers OR flat-out create a random re-mix making your 2 minute track sound "not looped" as in: it changes enough times it sounds like a track 10-15 mins long.
EDIT: separate the drums and a the synth pad... mute the drums when you are in a dark alley, when a monster jumps out and starts chasing you, fade in the drums... viola.. epicness ensues...