(currently on a different machine and location, so I am going to respond here)
Thanks for your quick answer, altough it was negative one.
You wrote, this functionality is not supported by Joomla. Really? If so, that's a real bummer. All those J! core and custom form fields possibilities (I've looked into the docs), and everything is backend only? I can't believe it... Is Joomla limited to that very basic frontend article submission? There must be a way around it...
I would like to hear your opinion and insights as a developer (i don't have enough details and knowledge about Joomla API and the future. Will it be improved to extend frontend forms as well?)
Yes, it can work, but custom layout is unique for each Joomla template and requires custom coding.
So it's not simple and most users won't use this feature because they don't have a developer