Exchange backpressure limits are not changing

We have a 2019 CAS Exchange server. https://learn.microsoft.com/en-us/exchange/mail-flow/back-pressure?view=exchserver-2019  to MS docs, it is possible to change backpressure limits. The config file is located in %ExchangeInstallPath%Bin\EdgeTransport.exe.config. True. I would like to modify the system memory settings, so in the config file in the <appSettings> (this is my guess no exact description or example how to modify it...) I added these lines:

<add key="SystemMemory.LowToMedium" value="88" />
<add key="SystemMemory.MediumToHigh" value="97" />
<add key="SystemMemory.HighToMedium" value="97" />
<add key="SystemMemory.MediumToLow" value="84" />

just to test. Restarted the trasport service and also the server, yet when I check, with Get-ExchangeDiagnosticsInfo command, I am still seeing the old default values.

Why? (also why is not properly documented? 😞 )

Thanks