https://atadistance.net/2019/10/20/japanese-text-layout-for-...
> Baseline font metrics will never deliver great CJK typography because there are too many limitations. > > This is why InDesign J implements virtual body metrics based on Adobe proprietary table information for true high-end Japanese layout. There is no virtual body standard digital font metric standard so everybody implements the missing stuff on the fly and everybody does it different. Unfortunately the irony of it all is that Adobe played a huge role in how these limitations played out in the evolution of digital fonts, desktop publishing (DTP) and the situation we have today.
I have a Kobo reader which supports both ePub 2 and ePub 3, and IIRC you need ePub 3 in order to get proper RTL/top-to-bottom text and Japanese typesetting, as well as proper comics support (if you buy an ePub 3 manga, it'll properly flip the page turn direction and the progress bar; a CBZ or other format won't). But most other readers I run into don't understand ePub 3 properly.
I find that reading vertical text feels better, even though I first learned to read horizontal text. I don't know if this is all in my mind, or it really does have some appeal to it, though.
Maybe it’s because 99% of my Japanese context is business-related or on devices (computer, phone) and I don’t read novels, manga, etc.
I'm not sure how I'd feel if the vast majority of my usage had been horizontal instead.
That is the only one I've encountered though.