On Template_talk:Extension you might be able to see how I miserably failed to fix a typo in topic Imcompatible with Template:EL with the help of {{delete|typo}}. ~~~~
Topic on Talk:Structured Discussions
Hmm, that should have been possible to fix by clicking "Change subject" at the top-right of the thread (e.g. in the new copy you made at Thread:Template talk:Extension/Incompatible with Template:EL). But possibly there's a Liquidthreads bug that I'm not familiar with.
Regarding Flow, is/was it easy enough to find the "Edit title" link in the topic's actionmenu?
If that exists I certainly missed it, that's why I pulled a {{delete}} and reported the issue here. But there is a good chance that it's only me, because I wanted to fix my typo immediately. And of course I know and like the "talk page culture" as is, that's orthogonal to the Flow design goals: When I have to fix my colons in talk page indents I have an idea why you are trying something new ;-)