The actuators are just a motor, they do not have any control electronics included.
It needs a power control system of some sort.
Unless that is proportional (eg. the motor speed is proportional to the position error), a slow bend of the sensor would result in a series of full speed "jerks" with the motor continuously starting and stopping.
Trying to position something accurately like that is likely to cause ovrshoot and oscillation.
I somehow doubt that's what you want?
The PCB is the last part, you need to prototype the control circuit and get it to work exactly how you want, before committing it to a PCB.
It would need feedback from the motor pot and compare that to the flex position, so it can accelerate for large movements and slow down to an exact stop, or smoothly track slow movements.