As a workaround for sync issues between shairplay audio on Linux speakers and VLC video on iPad OS, there is a manual “audio delay” option under “playback speed” settings (reachable from a running video). I found that -1000 (i.e. a negative delay) worked well for this one show I was having issues with.

Volumio is an open source audiophile music player. It is designed and fine-tuned for high-quality music playback and it runs on a variety of devices such as Raspberry PI and other microcomputers as well as PCs and Notebooks.

airplay in Node.js