How to inject into dynamic iframes?

[TiborUdvari]

Is there a way to load the extension/polyfill after an initial load?

I'm using web editors that load iframes dynamically once one presses a "play" button, notably the p5.js web editor.

Here is an examples through the p5.js web editor: https://editor.p5js.org/TiborUdvari/sketches/G1S1g40xx
The same example working directly: https://www.tiborudvari.com/sketchbook/spatial-computing/hello-box/index.html

I'm no expert in web extensions, but I'm guessing this is where the polyfill actually loads?

immersive-web-emulator/src/extension/service-worker.js

Line 32 in 7abf503

runAt: 'document_start',

I also noticed it was the code that is near #11.

What would be the best way to approach this?

For some context, I'm working on a way of doing live coding with webxr, like this, but for development purposes it would be great to have it working with the Immersive Web Emulator.