pi-Stomp has never had any intention to work with pisound. The 3 audio cards that pi-Stomp does support (IQAudio, AudioInjector and HifiBerry) all share the same pinout, but pisound has its own which is not compatible. The GPIO's that pi-Stomp expects to use for encoder inputs, footswitches, relays and the SPI bus for the LCD, pisound uses for its own purposes. Doesn't mean you couldn't use it with pi-Stomp, but I believe you'd have to disable so many pi-Stomp facilities (the LCD being the most significant) that I'm not sure what use it would be.
But if you must, feel free to try.
Hardware aside, I'm also not sure if pisound can be installed upon Raspberry pi OS. Do you know if that is possible? If not, then any debugging of logs is futile because pisound would never be happy.