Iframe embedder - no permissions, no relative paths
Iframe embedder (1.0.22) doesn't allow to use permissions on iframes. This permanently and irreversibly blocks functionality of recording audio and video inside iframes. At least in Chrome. Thus I consider it a bug, not a feature request. For more information see: https://dev.chromium.org/Home/chromium-security/deprecating-permissions-in-cross-origin-iframes
Moreover iframe embedder doesn't allow to use relative paths. It should at least support this type of relative content: src="/web/index.html" - index.html is located in the web folder at the root of the current web.
Ordinary iframe supports both permissions and relative paths, so it should be relatively easy to correct this in iframe embedder.