Unfortunately, due to restrictive working practices and agreements we are unable to do this. Because we bid for working positions on seniority, it would throw a cat amongst the pigeons to suddenly decide on the day that I would like to work in First. Being honest, I can't imagine many CSDs opting to work in WT voluntarily!!
Are they not "custom and practice" rather than an actual rule? Anyway the CSD is the most senior by definition, yet is the only one who doesn't have a choice of working position. At briefing allocate the junior positions first, then decide where you need to be so you can do IFA's (so they can't subsequently avoid you!) and the pursers then choose their position.
I think it would be good to shake up the system a bit, many are too used to working in one cabin all the time.
I think your time would be valuable in WT as well. They are all customers!