That covers your bases, gives the user an option, and doesn't violate any standards that I can see. If a standard banning Launcher install re-emerges, you won't have to do major surgery to your spec, and it will degrade gracefully.
Does that satisfy any|everyone?
Isaac, thank you very much for your response!
Now I can get rpmbuild to successfully use rpmbuild with xdg-desktop-icon in %install... and in the process puts an icon on my desktop (before even installing the rpm!) I am doing something wrong. Any suggestions?
Here is the relevant part of my spec file: