I just updated code to improve handling of clone MP3 module (I still recommend using original from reliable source) and a fix for SpikeOut.
All precompiler are available in the GitHub for DSB2, DSB1 and Spikeout.
Having a "hacked unibios" with a "reboot to menu" option would be great addition.
Or maybe just hack the "soft reset" option to reset to menu by default, I'm not sure if any side effects could occurs with original games.
I think all of the adapter we made are 4 layers, and flex are 2 layers. We could arrange another layout for routing but place will still be limited.
Also, flex are very expensive. It's cheaper to waste few PCB than create flex.