MTO multiple times with same team??

Can I play multiple times with the same team at dif reward gates and still get rewards both times? Like I have been doing veteran mostly but considering starting an all star. But if I havent done a team in veteran and I go thru it on allstar will I then be unable to do that team on veteran since all star is more difficult?

No I believe you should be able to repeat MTO on any difficulty as many times as you want and still get rewards

Has anyone done this successfully?

By the time you reach 70/70 you shouldn't keep playing it unless when they release stage 2 then you can do new MTO.