What drawbacks can I expect from keeping two twin seeds?

More likely than not, one will grow substantial faster than the other and shade out/stunt it's sibling. Predicting outcomes is honestly a crap shoot with "normal" genetics, mutations lend a curve ball all of their own.

You may have to expect growth being a little bit slower and not getting as much yield out of it, unless you plant them in a really big container where their roots will not compete for available soil... But i am supporting experiments, so ´give her as much soil as possible and go for it! Good luck! 😉

I said something stupid, one of the two is a clone of the mother, they are not twins 😉

All twins I have grown have been either hermaphrodites, flowered really weirdly/poorly.............or both. These days, any twins I get, get the chop as soon as they are "born", I don't want to waste my time and space growing hopefully maybes!

None. This platform has a winner with double sprout. I had few myself too. Some say get rid of weaker one, but you have to grow it yourself. Mine ; growdiaries.com/diaries/184733-grow-journal-by-asnoriu growdiaries.com/diaries/127642-grow-journal-by-asnoriu/week/723137 Winner growdiaries.com/diaries/123073-grow-journal-by-zurban-poisonia Have fun !

It's an interesting mutation, it's called polyembryonia. There are two embryos in a seed, it can happen even with 3 but it's very rare. You will have one of the two plants that will be slightly smaller than the other. But genetically they are twins. It's going to be very interesting to follow 😉✌️