I think reference tuning should (or at least could) be musical. Unless you take refrence to mean it's just a monitor tuned to show an engineer everything that's in the mix, in which case it's probably tuned for clarity and accuracy above all else (and usually at the expense of an enjoyably boosted bass response).My last demo session with Traillii is a long time ago, and I would want to spend some more quality time with it to draw the conclusion.
Maybe the question is: If an IEM is identified as being “musical”, does this automatically mean that it is not referencing tuning? I have seen similar arguments on the reverse side - U12t and VX are both accepted as reference tuning and music production-focused, and both are far from being musical.
I don't think there's one standard definition of 'reference' because every engineer will have a set of speakers (more likely than IEMs) he references to produce the final mix. And as far as I know, there's no hard and fast baseline for a reference tuning for listeners (we can't even agree on eartips and you want us to agree on what sounds 'accurate to the recording'?).
So to answer the original question I asked, you have to decide what constitutes 'reference' for you? But, more importantly, if that type of tuning is more or less enjoyable to you than Traillii (or any other IEM for that matter), or if the benefit for you is not so much in the enjoyment but in having an IEM that you consider to be 'reference'.
And now I need some coffee...