The first Clip train is now available for full service, subject to driver familiarisation, and as such can be allocated to any working.
The 141/142 series are generally used for the trains still undergoing in service testing, to keep them close to Hainault, and there are specific test paths numbered 151 and 152 to allow them to go further afield.
As an aside, “running board” isn’t a term known or used within LUL. The three digit numbers used here are train numbers, and there are others that are associated with crew duties.