Drawback with using AJAX method: It becomes complicated if we use change_detection to detect deletions or edits.

This could be a personal error on my side. I might have included quick reply / comment box by accident into the internalise_ajax_screen function.

Not an error of yours, it does work via including the whole Composr page into the iframe.

I agree with 'b'.

This was implemented by Salman way back. I've just reviewed, it looks good.