Web Audio MIDI dev
Scheduling
The most accurate way to schedule a function in a web browser : https://medium.com/teads-engineering/the-most-accurate-way-to-schedule-a-function-in-a-web-browser-eadcd164da12
TL;DR
The setTimeout function is okay, but overall, for a 250ms theoretical timeout, the real/effective timeout value ranges from 251ms to 1.66+s.
As of October 2020, the most accurate way of scheduling a function/callback is using the setTimeout function in a Web Worker, in a cross-origin iframe.
The requestAnimationFrame function is the least accurate and requires to be inside the viewport, otherwise the real timeout can go up to several seconds, or even minutes.