Hi,
Thanks. What you hear is the side-effect of this type of articulation. We have recorded longer quick phrases and extracted the transitions, which may also include a ringing decay of previous notes.
These articulations are designed for very quick passages, which are usually also not played 100% clean, in real life. Under scrutiny, you will hear the side effect and you can point it out as a mistake... but there is no other way we know of to get this kind of result. Trills will always be tricky when played without performance trills (quick legato transitions with a round robin of transition options).
In other words: It's not a bug, it's a feature!
Best,
Paul
Paul Kopf Product Manager VSL