Have I then the possibility to correct this values if I am out of this minimum or maximum tolerance?

Not that I know of. The tables are not in external file, and are (IIRC) a part of player SW, not kernel, so, save for some very elaborate kernel manipulation of /dev/ttyS0 data stream, we can do nothing, I am affraid. On the HW side, I don't know whether Sony stalk yields to resistor bank surgery. Has anyone tried to open it?