The force sensors are designed to work at full sensitivity in the center of the buttons, so clicking on the edges means it may not register full force.

The sensors are calibrated at the factory so that the readings are the same on both the left and right side, but over time, the calibration can change. Causing the percentage values to read differently on each side. This can often be addressed by adjusting the force thresholds individually for each button. But if any of your deep click buttons are not giving you access to a useful pressure levels (e.g. if it hits 100% too soon). The you can re-calibrate them in the X1 Control Panel.

The force sensor calibration tool can be found by clicking the mouse icon in Simple Mode, or via the main menu in Expert Mode.