I'd been planning to use it with the Feather M0 Bluefruit, but for now I'm testing with an M0 Express with one of these LED displays next to it [1] on a board doubler. Good to know that this is more temperature rise than you'd expect to see; I'll have to confirm that (and measure the thing's current draw, which I have not had a chance to do yet). Thanks!

[1] https://www.adafruit.com/product/3132