I use 10ohm/ 0.5A indicative of a typical smartphone.

There are no electrolytic capacitors inside the case. The D1 design requires the 21V limit, which isn't as efficient at higher speeds without a load attached BUT offers significant efficiency gain at lower speed and/or with a suitable load. That is the trade off, and one I was happy to make because the majority of tourers and commuters are not doing 35kph+ on a constant basis and they tend to buy dynamo hubs to power things. I've already done the alternatives; load dependant darlington shunt, and high voltage PWM (crap at low voltage, low output, less efficiency - Igaro D1 PWM is 95%).

On heat, here's how much it generates from an actual user (see last post):

https://www.lfgss.com/conversations/289960/

The Plug monitors the output voltage and cuts off if it drops. It does not have the capacitance or efficiency to continue over the transients hence it's poor performance at low speed. The ability to function at differing speeds is outside the scope of my pdf test.