I was wondering why you make this one:
https://www.adafruit.com/product/2488
And not a 32u4 version?
I really don't get why the community sticks with using UNO R3 designs, I think it is obsolete. I banned the UNO's from the books I write and from our classrooms in favour of 32U4 boards, but I can't shop those in regular R3 layout at Adafruit, a company I really like to turn to for a much better user experience.
The most simple example why 328 sucks is UART in combination with the basic Serial Passthrough demo sketch. Things like MIDI, GPS, GSM, all work straight out of the box with a 32u4, whereas you always need to configure software serial ports with the 328.
Then there is double Analog in, hardware SPI not consuming pin 11-13, USB-HID support, especially the HID support is loved by students.
So please, ditch the 328 and make it a 32u4 board!