Hi teed,
As has been stated, the Delta time is not ideal as it affected by framerate, which can certainly throw off a metronome if you have a faster/slower pc than others. As a musician myself I understand the need for consistency and accuracy with a metronome system, but unfortunately I have yet to find a solution that is consistent and exact. Please let me know what you come up with as I’d be very interested in seeing what you are able to do!