Can she jump back to JSA?

A decision was given to end a claimant’s JSA for failure to attend an interview.  Quite seperate from whether this was a good cause issue, the claimant claimed UC prior to lodging a Mandatory Reconsideration request about the JSA decision.  Now getting UC, she has had a non-dependant deduction made to her UC Housing payments that was not appropriate under JSA/HB.  Assuming that the MR request overturns the JSA decision, will it then be possible for the claimant to jump back to JSA and to relinquish the UC?

Indeed, is the MR request a valid one as it was made after the UC claim was given?

Any help greatly appreciated.

Thank you.

Patrick