there was a point where I could do both, but that was a long time ago. Now, I'm really glad these programable keyboards are around, I can make Dvorak native keyboards and not worry about configuring the OS.
Your brain does not really know where keys go, it's more of muscle memory. I find that I can type on different feeling keyboards with different layouts quite easy.
As for the Planck, do you program? Will you miss the numbers? If not, go for it, it's a fun keyboard. Do it MIT style (two buttons instead of one 2u space bar). You have so few keys, might as well get as much out of it as you can.