You are correct, my apologies for being wrong.
In the end it always comes around to romsets for this issue.
The reason standalone application works(most roms depends on merged/unmerged/your romset) on an automated front(including on amberelec) is because it generates and uses a shared romset(shared meaning it can work with quite a lot of roms regardless), Retroarch doesn't however.
So there is nothing wrong with Launchbox, Retroarch is a bit bad in dealing with romsets but the biggest issue is how Final Burn Neo is developed and created to work.
FBneo is very user unfriendly and poorly designed and implemented and this is the biggest flawed emulator today out of all of them (arcade is the worst to get working), if only a proper programmer can program FBNeo to be user friendly with a self automated rom database scan and setup while taking in all variables (emulator version, romtype, rom game and prerequisites, all rebuilds, from a online database for example) (so basically like FBNeo Nightly which does most roms like what I just described but also with the ability to fix the remainder that are marked with a red circle of unavailability due to incorrect romset)
That way more people can use it instead of just the "elitist trolls who "just" say to you to require a programming degree" /sarcasm
Otherwise mostly all will give up.
I have also read forum posts from the FBNeo devs which show elitism/immaturity, also the "THIS IS NOT A BUG" on the fbneo screen when romsets fail is also an indicator of this personality, not someone to be able to get along with, which is a detriment to emulator development as they refuse to fix the end user experience.
Edit: I have seen hundreds of romset issue posts on lots of forums, theres quite a few here on launchbox too, it is a common complaint