It isn't differential input but the BNC adapter for the Analog Discovery is a useful addition.
For now, I'll start by cobbling together a 2+2 4mm banana jack panel I can connect to the Analog Discovery 2, and use the two differential channels using cheap probes. I really only need sub-MHz bandwidth for now (for investigating power rail noise and glitches in various projects that have stalled due to lack of test and measurement equipment!), but I definitely need the differential probes.
(A 16x2 (8x4) panel with standard separation between each pair would be even nicer; you would then get every pin on a banana jack. At a standard 0.75" grid, it'd be about 7" by 4"; might make a nice cover for the AD2.. Or maybe I could do a fanout from a short 34-pin ribbon cable?)
If I was using a say Rigol DS1054z without true differential probes, just using two separate channels and display math to measure the voltage drop of a 0.01Ohm resistor at 5V, I would not get even one-ampere resolution (because 1A drops 0.01V over a 0.01Ohm resistor, and the scope resolution is at best 5V/256 ≃ 0.02V, 0.04V at ±5V range). What I would like to do, however, is measure and record the voltage drop over that resistor, and the 5V voltage itself, at say 100 kS/s to 1 MS/s continuously at maybe 0.05V and 10mA resolution, to see how each supply copes with different loads, as well as whether there are problematic glitches. And if glitches do occur, whether added bulk capacitance or a pi filter (on SBC input) fixes it. I can do that with a Teensy 3.2 using my own circuit, but I didn't have anything to compare against and verify my circuit.
If one of my ~$10 DC-DC modules with an inhibit pin can provide max. 6A at 5V continuously without glitches (as the current demand is quite variable, 1A to up to 6A in short spikes), I can finish my Odroid-HC1 microcontroller carrier project: a Teensy 3.2 microcontroller that can be used for serial console, external display controller (either a cheap small TFT or OLED, for status information), external GPIO (the HC1 has none!) for a couple of buttons etc., monitoring the current and voltage supplied, as well as turn the Odroid-HC1 (or C1+ or XU4) off and on at desired intervals, keeping just the microcontroller always powered on.
It is amazing how hard some problems are, when you don't have good test and measurement tools!