[AceOfSpades]

So I've found one potential way to fix this. In the Hero Lab editor, when viewing a class, there is a section where you can define which FCBs that class has access to. Similarly this section exists for races as well. This then leads to a situation where each class only links to the FCBs or the core races (there are still racial checks in the FCB things) and your character has to be the race (if not core) relevant to the racial FCB to even have the option.

It seems like a simple fix would be to modify all existing classes to point to all relevant FCBs and let the expression requirement script handle race reqs. Then remove any option of choosing FCBs in the race tab. As this has not happened I assume it is more complex in the back end. I have tried this with the alchemist class (which was a pain as I had to recreate it as a custom class) but then I could choose any alternate FCBs for any race at all. I'm not sure what broke. I am going to test it with a non-supplement class that I can directly edit and see what happens.

Update:
Tried it out with a core class and I ran into the same issue. I also realized that I can't see what Hero Lab is using in the editor with a core class because, when choosing Create(new) to open a class it only copies over parts of the class, FCB not being one of them.
I tried to load in the Paladin class, it didn't carry over the core FCB options, so I bootstrapped all of the FCBs for the paladin class. Save it as a new class, created a character with it and 'lo and behold... I can't choose ANY alternate FCBs. So there also appears to be a greater problem here where custom classes can't access existing altFCB options properly. Or I'm missing something in the editor. Will file bug report for that one.