10A isn’t the max current the 50E is capable of but what the manufacturer is saying to stay at or under for continuous discharge, it can be more than that, case in point if you short circuit it it will likely put out a lot more than 10A, DC internal resistance (DCIR) of the 50E is ~30mΩ, with a perfect short that’s 4.2/0.03 = 140A, likely less though, as DCIR can get higher at very high current, and you can’t do a 0Ω short.
In a direct drive led circuit the current is going to be dependent of voltage between the led Vf and cell, and the resistance of the circuit, : the cell DCIR, contacts resistance, springs, wire, traces, mosfet resistance, and the led current/voltage curve, which doesn’t really behave like a resistor, it would be higher at low current, and lower at higher current, between 2 and 2.5A it sorts of looks like a 40mΩ resistance
so :
50E : 30mΩ
spring : ~8mΩ (I measured the PL42G2 spring at 4mΩ each, likely less when compressed, I assume the E07 uses the same springs)
mosfet : I don’t really know, they can be pretty low, like 2~5mΩ ?
7 E21A at more than 2A : 40/7=6mΩ
others stuff : maybe less than 10mΩ ??
total : 59mΩ
E21A Vf at 2A = 3.09V
full cell at 4.18V
(4.18-3.09)/0.059= 18.5A = 2.64A per led (some more, some less due to Vf differences), and the 50E is overdriven
But that’s napkin maths and some resistances are wild guesses (and please correct if I’m wrong somewhere)
Another way to look at it is that in order to no exceed 10A with a full cell, the circuit resistance would need to be arround 110mΩ.