I haven’t used my espressobin yet – no time so far – so this is pure theoretical.
http://espressobin.net/wp-content/uploads/2017/02/ESPRESSObin_V4_Schematics.pdf
There is a schematic which shows both the 12V jack and the usb power line “+USB5V”.
Through the chip UP7534DMA5-15 the microusb powers ONLY the +5V line.
+12V from the jack goes to J4 (BIT5 – MOLEX) and to the chip RT6220 – a buck converter – to feed the +5V line.
So it should work – if your 5V 2A powersupply is of good quality. With RaspberryPi there are a lot of issues with powersupplies rated for 5V/2A but can barely manage 1A
