Currently i have created in my library an app.config file builted like this one:

```
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
<appSettings>
  <add key ="DATE" value="dd/MM/yyyy"/>
  <add key ="TIME" value="HH:mm|HH:mm:ss"/>
  <add key ="DURATION" value="ss|mm:ss|hh:mm:ss|hhmmss"/>
  <add key ="LAT_LONG" value="dd.ddddd[N,S]dd.ddddd[E,W]|[-]dd.ddddd°,[-]dd.ddddd°|[-]ddmmss.ssss, [-]dddmmss.ssss "/>
</appSettings>
</configuration>

```

I need my user to modify this settings by adding and/or removing format and even adding new settings to the file. I'm using `ConfigurationManager` to do that.

Now i have a doubt that this will actually work when this app will be deployed, cause, if i understand what i read in my previous research, `appSettings` cannot be modified at runtime. Do i have to use `userSettings`? and in that case can i add them directly in this `app.Config` file? how exactly work `userSettings`? Can i interact with them with the `ConfigurationManager`?

EDIT: ok i understand that i've asked a lot of stuff, so let's make the thing simple. Can i add userSettings node to my app.Config ? If yes, do my application work actually on them?