A more detailed explanation of the keys mentioned above:
MaxNumOfMessages: Purpose of this key is how many messages are to be displayed on the message section in the probe GUI. By default, its value is -1 (i.e probe display all messages as per previous design of the probe). If the customer environment has lot of old messages then the customer can enable this key, and can set how many messages he wants to display. Less number of message leads to minimum processing. This will also help reducing the CPU Utilization.
setPosToEndOfFile : By default key value will be set to "no".
After setting this key's value as "yes", probe will work in update mode. After enabling this key, the probe will jump to the end of the history items and process only updated items. With this, we can avoid processing of lots of old history entries. This will be one time activity i.e on first deployment. After this activity, the key will automatically set to "no".
For more details, please also check the probe documentation, found here: