I actually think that saving the combination for last in the short is not worth it. The risks are too high. For Anna, I would think it's a better strategy to do a 3F+3Lo as the second jump and save the 3Lz as the bonus jump. She will lose 0.49 on that, but that's nothing when you think of the bigger picture. Also, if she misses the combo, the plan B could be a 3Lz+3T.
Missing the combo, like Sasha did at Worlds will be a 10+ points loss. That's a lot going into the free. I don't think anyone should take that risk.
And as for Loop combos, as much as I love them, I think they are criminally underscored by the ISU. It is SOO much harder to do a 3Lo instead of 3T in combination. And all you get is +0.70!! It's insane.