Live Service to Full Service transition period,  changing back to legacy benefit ? 

Sorry if this has been answered elsewhere but I just want to double check. Is it correct that if during live service you claimed UC as single JobSeeker (due in this case to ESA ending) can you now end your UC claim and claim JSA again, before Full Service starts. The advantage being that just awarded PIP and will get DP and further if, as likely Job Seeking carries on will eventually migrate with DP protected.  Anyone actually done this in practice please ?  Also any thoughts on if UC claim remains live in anyway and you end up getting swapped back when it goes full service (I think NOT but it was mentioned to me as a possibility ! ) Sadly it looks like only SDP getting protected, not all the DP’s ?