I tried searching for my issue but haven't found anyone quite as stuck. I'm currently experimenting with a Raspberry Pi 4 and a HiFiBerry sound card. I'm also using JACK so I can route audio between applications. Unfortunately, I cannot seem to get Stereo Tool to start at all, it immediately fails with a segmentation fault.
pi@raspberrypi:~/Downloads $ ./stereo_tool_gui_jack_pi2.1
Thimeo Stereo Tool 9.70 (for Linux with Jack) (C) Thimeo Audio Technology, 2001-2020
My JACK server and QJackCtl are running, so I don't think it's a problem there. The ALSA version seems to run just fine, but obviously cannot interface with JACK.
Please let me know what else I can post to help diagnose this issue.