I wonder whether this is
the board game Tak,
which is published by
Cheapass Games ("miserly posterior").
A fantasy duel, your mind your weapon
It's an abstract game for two, so (1) a fantasy duel in the sense that whatever wranglings you might take it to symbolize are in your head; it's derived from a fantasy novel so it's (2) a fantasy duel in a more literal sense. And of course your mind is your weapon just as it would be if you were playing chess, go or Scrabble.
From the undubbed anger of a persnickety man and those of the miserly posterior.
Second half is definitely Cheapass. First half, I'm not sure. The game is inspired by a book called "The Wise Man's Fear" by Patrick Rothfuss; the actual game design is credited to James Ernest and Patrick Rothfuss. I don't see how any of those names quite fit the first half yet.
To the edge or the center, where best to place?
One of the primary game mechanics is the placing of new pieces on the board.
Weak and strong towers, concentrations of strength.
Pieces can be moved on top of others, forming towers. Taller towers have longer-range influence.
Roads now walled off, to the capital crush.
The goal of the game is to create a road from one side of the board to the other. One category of pieces is known as "walls". Another is called "capital stones".
When we go slow there's beauty, no need to rush.
I guess this just refers to the fact that strategy games may be played slowly and (for aficionados) a good game can be a beautiful thing. Or is there something else going on? ... I see that their Kickstarter campaign was titled "Tak: a beautiful game" which is maybe part of it.
First hint: It's fairly obscure
Well, it is. I'd never have found it if I hadn't suddenly spotted the Cheapass reference.
Second hint: It's relatively very recent
Subject of a Kickstarter campaign that finished just a few weeks ago.