You put in a lot of work there.
I think the final decision taken on this was for good, also, a way to have something different from the blogging layout where we fix images where we want them. What I miss is the HTML for images and text but I still think we can find one that will work since the one I used in my blog posts to write a little "about me" at the end of my blog posts is still intact.
You can only use Markdown and that‘s it, nothing else to be found, meaning no centering possible! I wouldn‘t want much, just to decide to left-align, center or right-align my stuff on my own and where to put it. I also asked about this on the peakd discord and their excuse was the comfort zone of new users and what their used to 🤦🏽 boring conservatives!
PS: Check out Markdown so you know what‘s possible … https://www.markdownguide.org