Mmm, no answers?
Since it opens on the same layout each time, can I set a script trigger that when that layout opens for the first time to go to the home layout?
It seems funny that FM comes up with a way to post to the web but not tell the site which layout to start on.
Field Options in the FileMenu can be set to specify a layout as the first layout seen when the file opens.
OnFirstWindowOpen, a trigger that you can specify in Field Options, can also run a script--which can select one layout for WebDirect clients and a different one for FileMaker Pro clients if you need that sophistication.
That did the trick.