I have a question about how to sample-accurately "forward-schedule" playback of audio from any point in the audio file and I'm presuming that your advanced audio player is our friend?

Our advanced audio player has a cachePosition method. If a position is cached, jumping to that position and starting playback is instant. However, we have a simpler way to sync players. Please check the cross example project in our sdk. It uses a master bpm value to sync tempo, and a ms-elapsed-since-last-beat value to sync to an imaginary beatgrid.