Whoa, second mode? I don't remember a second mode... Hmm, sounds interesting! Yeah, looking again at the ADP1653 data sheet, it only seems to support integer values between 1 and 11 for "torch mode" usage, 1 representing the low value of 50 mA and 11 being the high of 200 mA. (...) So only the low value of 50 mA is supported. I'm still not seeing any way to go lower than 50 mA here...
What is the fastest the LED can flash in the strobe mode? If fast enough (say 25 times per second or more), then lower values could be achieved by varying the duty cycle. (...) If I get it right, timing is in multiples of ~54ms, totally unsuitable for emulating steady light with very fast strobing