As far as I know, those URLs above are the only/best way of
overlaying HTML in a Flex application.
Currently the HTML control is only supported by AIR, although
this is a common request (migrating the HTML control to Flex), and
I believe there is an enhancement request filed already in the
public Flex bugbase (see
https://bugs.adobe.com/jira/browse/SDK-11869). I recommend voting
for the bug so we can accurately guage community interest in the