Go for it !
Any chance of advancment should be looked at and WSO would seem to be a logical next step.
Once into a "flying job" you may find that you want to take this further, I know of at least two rotary crewmen who are now flying jet airliners thanks to the help from RAF flying clubs, I have no doubt that flying as a WSO had a big influence on the employment process.
What ever your plans for the future I don't think you will ever regret trying for WSO.