This is my personal layout which I use to test out ideas which may or may not make it onto the default layout we ship with. It's based off the default layout, with various tweaks.
* Makes bottom-right key send minus/underscore when tapped, L1 temporary toggle when held
* Tweaked the positions of the numbers on the symbol layer. Basically, 12345 are now directly under their number-row counterparts in layer 0. You can imagine pulling the number row down to the home row. And 67890 are directly under 12345 - so it's a matter of just adding 5 and going to the next row (1+5 = 6, 2+5 = 7 and so on).