Sergio, Thanks for this post.
The only item I see worth confirmation is pushing the solutions through one of the check valves, just to be sure. I notice on the calibration photo the other end of the pump is open. Not really how your using it any longer as stated. I would assume a bit more resistance with check valve. Haven't used one of these pumps yet so not able to confirm over here.
You have raised the bar beyond the use of ADA products.