And here’s the second mod that was needed, 10 minutes with a common solder iron, this is the easiest host ever.
The led is the bit higher current-capable RWN05-32K-C-EX from rngwn (see link), I measured 3007K, 97.2CRI, R9 97 and duv –0.0034 for this particular led ( 
, how nice can a tint get?)
The 220 resistor was replaced by a solder blob, the battery current went up to 135mA and the output was better than I thought: 25 lumen on a alkaline and 21 lumen on a old crappy NiMh. A major brightness update over the 7 lumen stock.