Totally not necessary to cut. Any trimming you do is purely aesthetic or only cut the dead wood. They really are fabulous trees when allowed to mature to its natural form even in winter with its gnarly, curly, twisty structure.

if they are dead woody ends just snip them off with secateurs. But if just the bare ends after the leaves have fallen then do nothing. if in spring there are no leaves then prune back to where you have leaves.

Thanks all