Funnily enough, after writing that, I had a session bringing in some old posts and doing far more in a text editor rather than in the Grav front end. It proved to be a much more satisfactory an experience overall. I think if I build up a few snippets that allow me to easily produce the YAML front matter that slightly different posts require, then that will be the way to go. I still need to use the front end to check that everything is working, especially where there are images, but other than that, I think it is easier.
Glad you like the tweaks to presentation.
My big task now is to enable comments, so that I can enable webmentions. I'd like to make some progress on that before IWC Nürnberg.