We are currently in the Blueprint Phase of an ESS project (Working Time) using the latest and greatest Web Dynpro ESS service. There are several requirements that can only be met with modifications to the SAP Java code. I have read through several useful posts for doing these types of changes but would like to talk to a customer who has made these types of changes and has experience with SPs or Upgrades.
Please reply back if you would be willing to talk with us about that. You will get full points if you meet the criteria of a customer IT group supporting this at a company and you are willing to talk to us (no matter the outcome of the conversation).