feedrate Z-Axis?

[ralfg 5]

 

Hello
in Cura from version 4.2 there are new Start-G-Codes.
So I have in the profile a line "M203 X500.00 Y500.00 Z10.00 E50.00".
My first question is, what is this line for?
 
The option "Maximum Z Speed" was replaced by "Z Hopp Speed". According to the explanation, the speed at which the vertical movement (Z-axis) takes place during Z-jumps should be.
But with me exactly this value is always used for the Z-speed. Stupid is, that you only see this option "Z Hopp When Retracted" is activated. If this point is not active, the "Z Hopp Speed" option is not displayed, but the value entered in it is used in the G-Code.
If this value is higher than the value entered in the line ""M203 X500.00 Y500.00 Z5.00 E50.00 ;Setup machine max feedrate", it is not limited, so the whole line there is obsolete. If I enter a 0 in "Z Hopp Speed", the value from M203 is not used either, although this is supposed to replace a missing value in the firmware.
Then with each Z-movement an F0 is written into the G-code.
Here the programmers have probably shot themselves in the knee. I'm sure they only wanted to achieve something good, I needed half an hour yesterday to find out where the feedrate for the Z-movement comes from. I didn't get the idea that I first had to activate a Z-hopp to find the hidden option with the wrong explanation.
 
Greetings
++ralfg++