Requires
Community ScriptHookRDR2.NET

Default Key: F10
Will display the status and the current values on toggle. 
Change values in the ini then toggle it on and off to update the values. 

Place the 
DifficultyScaler.dll
DifficultyScaler.ini

files in the scripts folder (Rockstar Games\Red Dead Redemption 2\scripts) (create if doesn't exist)