@RogerL, if you’re interested the code to build the PortableApps package is there: https://github.com/laurent22/joplin/tree/master/Tools/PortableAppsLauncher
To be honest I don’t expect PortableApps to ever accept the app (or most other apps) as their project is not very active anymore. The only person who can accept an app is John but he doesn’t seem to accept any, probably because it’s an additional maintenance burden for him.
If we knew they would accept the app, or if they had clear rules on what can be accepted or not, then we could work towards that, but as it is we don’t know anything (and I’ve never managed to get any clear answer from them) so it’s not a very good use of our time. But again, you’re free to give it a try.