I also think this kind of crash happens too much suddenly to depend on some warnings here and there (but I am happy they were fixed!).
The 3.0.2 was made against the SDL 2.0.3 library (which proved to works quite well) while this build from the github repository is compiled using 2.0.5 from LeopardPorts repository (
https://github.com/kencu/LeopardPort.../devel/libsdl2).
From what I have seen the new FS-UAE distribution rely on some new 2.0.5 instructions therefore I moved from 2.0.3 to 2.0.5 but this is the first compile I made against the new SDL2 library, maybe some bugs in PPC version prevents the library to work as expected. In the meantime I have launched a new FS-UAE compile session to see if something is about to change.