Please add a caution to the product description that Affinity can not handle Asian vertical writing.
On all stores - Serif store, Apple app store and MS app store, especially in Japanese
Many many users complains after they purchased Affinity and they put Affinity down on Social Media because of disappointment.
See these complains, this has been going on since long time ago and will continue until you implement vertical writing. https://twitter.com/search?q=affintiy 縦書き&src=typed_query&f=live