I find this to be THE achilles heel at the moment with the app, which seems VERY promising by the way. It's already part of our workflow and looks really good.
However, it lacks basic typographic refinement such as leading, tracking, adding different styles in the middle of a text and all that.
And a kerning button to activate kerning for fonts would be great as well.
Thanks for the feedback. We're glad to hear XD is already part of your workflow. I believe the following feature request in UserVoice is what you're looking for. It's in our backlog. You can vote for it and check the status of it through UserVoice. Thanks.
It's also mentioned in our roadmap document (see the second bullet > "richer text")
What's the roadmap for Adobe XD?