That was the 'blip it onto the canvas' approach :D I discovered that ImageBitmap type just recently too, it's been very handy for the little project I'm working on. My data still comes as base64 strings in JSON though.
Yeah you’re gonna have to async once to get the binary thing canvas works well with, but if it’s even remotely stable you can just memoize shuttling ImageBitmap back in as needed. For my use case it was just literally redrawing the same background image things get drawn on top of with an internal data structure that translates to canvas API. Switching from async calls to ImageBitmap basically made the difference between “this flickering is making me question medical facts about myself” and “I can see it lag if I’m trying really hard”. Which isn’t great but it’s more than good enough for what I was trying to solve.
