Here we lightly flush the flock age ewes, and hope for the vast majority to produce twins. Obviously we also get some singles and some triplets. Ewes are left to rear whatever they produce, with lambs lifted off triplets if they appear to be actively struggling. The only change to this is if I happen to be lucky enough to pass a set of triplets being born near a single, and i'll try to graft one on the single bearing ewe. Same if one losses her single, I try to find something to graft on to her. Hate having ewe doing nothing in spring.
We do not flush ewe lambs at all, as this gives a better chance of getting singles, this year every hogg dropped a nice single, which was ideal. As said, twins can be a pain for a ewe lamb.
I personally think they make a better ewe for lambing as a lamb, and are easier to deal with as hoggs, than maiden shearlings.
If every ewe here could have a single first time and twins every year after until se was about 8. . . . . i'd be a happy farmer!