It won’t help with dark mode, but the canvas-place-element proposal (https://github.com/WICG/canvas-place-element https://github.com/WICG/canvas-place-element)

It won’t help with dark mode, but the canvas-place-element proposal (https://github.com/WICG/canvas-place-element https://github.com/WICG/canvas-place-element) should allow those interactions on canvas-rendered text backed by a text element placed under the canvas.