Optimisation:
Make the character row into a ring.
It would also make it easier to find the optimal layout, as a few permutations are removed.
It would also make it easier to find the optimal layout, as a few permutations are removed.
That is, you have just invented the classic Dymo label maker :)
[1]https://www.staples.com/dymo-organizer-express-pro-industria...