Juliets in Earthbox too tall!

[soozbz]

Hi everyone! Black-thumbed newbie here. I am new to growing tomatoes and I've never been a star gardener--in fact, this is the first year I've ever managed to get a tomato plant to last more than a couple of months. So, please bear with me and my silly questions!

I've got one Juliet plant and one Celebrity in an Earthbox. The Juliet (indeterminate) keeps getting taller and taller, and it's showing no sign of stopping. Yesterday it finally busted one of the Ultomato rods off and bent over, nearly in half. I have both plants staked with Ultomato cages, which have worked well up until now. I tried shoving the Juliet back into its cage, and I added some string for a bit of (admittedly very minimal!) extra support. But, it's still leaning very heavily to the side. I'm worried that, the second a Texas thunderstorm rolls through, the whole thing will tip right over.

I'm worried that if I prune it, I might end up with sun damage (again, Texas). And I wonder if adding more stakes would damage the roots. I don't really have the space to put stakes in the ground instead of the Earthbox. I suppose I could try letting it bend over, but I don't know if that's bad for the plant. Any suggestions?

In the attached pictures, the Juliet in question is on the right. Note that it's leaning pretty heavily to the right! This is after I MacGyvered it upright again.