Combining a headset and an ESP32 for sound routing sounds like an interesting project! When it comes to using different libraries together, it can get a bit tricky. Have you considered tweaking the code or finding alternative libraries that might be more compatible? As for volume control using a potentiometer, that's a neat idea for fine-tuning! Bummer about the SD card not cooperating, but have you explored https://asmrmicrophones.com/ for any headset options that might align with your setup? They've got some cool gear that might fit your project goals!