Setting individual WFE config setting

Question

As per my understanding SPWebConfigModification class modifies the web.config across the farm, including all WFE. Are there any workaround to set some WFE specific web.config setting, like licence key or something using the above class

Answer 1

if (SPServer.LocalServerRole == SPServerRole.WebFrontEnd) { // Do your magic }

http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spserver.localserverrole.aspx

Answer 2

I politely disagree with SharePoint Dude because using SPWebConfigModification class requires submitting the modifications to the Content Service which applies the modifications across all web applications. That approach wont work.
I would suggest using a something external to SP to modify the web.config in that approach, i.e. PowerShell remoting and then transform the web.config file using WebConfigurationManager class directly.