Raphael,
I am aware that Vertical Layout is working as intended, so it vertically flips only Asian characters and everything else is flipped for 90 degrees to the right.
But the issue is how to write, for example, numbers vertically aligned within Japanese text.
And Roman names vertically aligned within Japanese text.
The solution we came up with is that for variables that we know are numbers and Roman letters, we used another font which flips every character for 90 degrees to the left (for example StraitSide.ttf), using that with Vertical Layout we get every character in vertical position.
If there is some other solution, please, let me know.