Worker thread support via OffscreenCanvas is a great idea and WebGPU does support it. I haven't tested ChartGPU in a worker context yet, but the architecture should be compatible - we don't rely on DOM for rendering, only for the HTML overlay elements (tooltips, axis labels, legend).
The main work would be: 1. Passing the OffscreenCanvas to the worker 2. Moving the tooltip/label rendering to message-passing or a separate DOM layer
For your use case with heavy data munging, you could also run just the data processing in a worker and pass the processed arrays to ChartGPU on the main thread - that might be a quicker win.
Would you open an issue on GitHub? I'd love to understand your specific workload better. This feels like a v0.2 feature worth prioritizing.