Cheers DD, It's a bit tight on the balcony when trying to get around the plants to foliar feed or even just water them, sometimes you bump into one plant when tending another. Perhaps a recent 'bump' caused the split.Hey ya. I see your concern. They are hardy though and lucky for us they can take a punishing.
I would lay a short pencil over the split then tape it firmly to the branch on each side with electrical tape, closing the gap as the 2nd bit of tape goes on.
Also supporting across the top of the pot with a packer that can be moved to avoid the possible dampness issue.
It’ll heal, but you want those branches as heavy as possible, right?
Next time leave a quarter inch of stalk above the cut. That will stop it splitting.
Interested to see how others would deal with it...
Cheers