Just in case anybody else is interested:
I wrote a tool that reads the portable apps directory (configurable, defauls to c:\PortableApps) and adds them to the Windows 10 start menu.
Announcement is here:
It's written in Delphi 10.2, source code is available under the MPL and I am willing to donate it to the PortableApps platform if you are interested.
Very cool. Does it only work on Windows 10?
I haven't tested it on anything else, but I think it should work on any Windows >= XP, possibly even older ones.