Hi Ron,
I suppose part of the reason for this blog is to make sure this is understood and confirm completely that it's not available but also to partly encourage SAP to introduce this feature since I like nice design and don't like this dodgy solution. e.g. That note talks about nullable options for parameters in Function Import also, which are not available to set within SEGW which makes calling the Function Import a bit annoying since all parameters are required parameters otherwise. This also leads to bad design. That said, code can get past this but I think SAP need to show Function Imports the love 
Cheers,
Matt