I recently replaced all of the springs and clevis pins with a foam solution that produces similar results. A lot of the force goes into the elastic band and the depth of the ADCs is very important. With the ESP32-S2 I am able to obtain 1200 samples per second across all sensors or 100 samples per second for each sensor.

The resulting signals are not as 'loud' as I wished them to be but they are reading the movement of the muscles underneath the skin. Will be posting a video update with the pros/cons of this system for use in biometric muscle contraction detection of forearm muscles.