Hello.

WebMessaging (postMessage) seems simple but has quirks. Different browsers handle data differently (structured clones vs. strings). The biggest problem is sending messages to a newly opened window/iframe. You can't just send a message immediately; you have to wait for the window to load and signal back. This adds complexity, requiring the new window to postMessage back to the opener, which then sends the actual data. A workaround involves passing data via window.name, but this has security implications as the data's origin is uncertain and the name persists, potentially exposing data.