I added a PR for spine-ts:
Adding Web Worker support for spine-ts in the SharedAssetManager class, which is used in the Construct 3 Spine plugin. This enables us to use spine-ts and the Spine addon with Construct 3 in Web Worker mode (which can reduce FPS jank in a web browser, decoupling from the main browser thread.)
I did not do the changes in the AssetManger, as the C3 Spine plugin does not use that class, so I cannot test the changes (the changes also look more extensive there.)
Tested with the Construct 3 plugin in web worker mode and in non web worker mode on Chrome, Safari, iOS Safari.
The main changes for web worker: use fetch() instead of img.src, use ImageBitMap instead of HTMLImageElement, enable OffscreenCanvas instead of HTMLCanvasElement.
Construct 3 web worker description here:
https://www.construct.net/en/blogs/ashleys-blog-2/performance-isolation-html5-1512
