Hi, the easiest way to get your patch to autostart is to simply put your patch in a subfolder in /usr/local/puredata-patches/, use main.pd filename for the main entry file, or provide a ‘blokas.yml’ file for the patch, see Pure Data patch with parameters in the Pisound App for example.
Then run patchbox, go to module, select puredata and it will ask which patch to auto-start on startup, select the one you’ve prepared.
The Patchbox OS image is configured to use the Jack audio backend, you use ALSA in your script, it might conflict. Also you should use 48000, 96000 or 192000 for sampling rate with Pisound. The PD always starts with “DSP” off, in our script, we provide a special argument that enables it, see here (-send ";pd dsp 1").