It doesn’t look like there would be an enclosed hollow area which would cause the part to strongly adhere to the tank due to suction forces (see this thread for more info).
When you go through your part with the layer slider in preform, my bet is that there are some quite big cross-section areas which will also make it more difficult for the printer to detach the print from the PDMS after each layer.
I wouldn’t be worried about the printer making noise like that with a model like the one you are showing, it’s just due to the force required to peel the part off the tank.