I have been able to remove the read only rule on the customer field in Service Request so that a user can change the customer of the Service Request after it has been submitted (just like you can change the customer of an Incident). However, when you select a new customer, the Parameter tab with all the parameter details are cleared and the user will have to select a new template hence loosing all the previous parameter details information.
I have checked to see if there is any business rule which triggers to clear the Parameter tab but did not find anything. Is it possible to change the customer of a Service Request without loosing the parameter details information? If yes, how is this possible?