Just adding another +1 to this. I and my Japanese friends need this feature to properly lay out vertical text in designs. The workarounds don't cut it; there are subtleties (such as how the character ー becomes vertical when written vertically, and kerning/centering issues, never mind multiple vertical lines of text) that mean you can't just use the narrow text box trick. It's just not professional nor practical.
I'm a developer, I know adding support for different text layouts is a big task, especially if the code was originally developed with the assumption that Western writing conventions are the only ones that exist - but really, this is a huge market you're missing out on. That's all of Japan, China, Korea, and all the other countries that use CJK scripts. It makes business sense to prioritize this feature. Keep in mind that most users from those countries are not comfortable English speakers, nor do those cultures encourage feature requests/complaints.
So you likely won't be getting direct feedback from Japanese users, they will just quietly not use Affinity software because it's missing features they need on a daily basis. If you want to see what Japanese users think about this problem, try searching Twitter. All of those posts are about the missing vertical text support in Affinity software.
Here's the hilarious hack that some users are using to get vertical text support in AD, using a font with rotated characters and then rotating the text box to compensate.
Please consider giving this feature more priority. The status quo is pretty bad. Nobody in Japan is happy with this, they're just yelling it out on Twitter instead of posting in the forum because that's the culture here.
