iWriter Pro has been another good alternative for me.
My go-to markdown editor is Bear, and it works on all Apple devices. It might suit your purposes too. Bear
I realise this response is a little late but I post it incase there are members like me just catching up on some of these posts.
The developer of Taio has ceased supporting the app. I’ve already experienced issues on my Mac after the Sequoia 15.2 update. The iOS version still functions fine (but for how long).
Taio was, I believe, THE best Markdown editor, especially for iOS. It’s taken me forever to find something similar. I’m using One Markdown on both iOS and macOS. One Markdown does not have all the features of Taio but I’ve got most of the missing ones using Shortcuts. Also the One Markdown developer is no where near as friendly as the Taio developer was.
Regards,
Peter