I think you have the right idea, protected cells would likely trip. From what I remember, you don’t often get more than 6A to the LED in DD. If the cells you have/interested in specifies tripping current of 6A or greater, you should be fine. What size cells are you thinking of using? Any particular reason to use protected cells?
I’d suggest using matched sets, checking discharge voltage of each cell, and doing capacity checks to make sure they remain matched sets. As long as you aren’t pushing the discharge voltage to the edge then you should be fine.
This is my thinking as well. If you’re likely to use the light till it dims then you’ll have to be very specific about the pair of cells used. If you don’t drain the cells (how I do it) then equal open circuit voltages is a good enough ‘match’.