I think it is interesting that even though John and I seem to have similar chert types there is still many parts that are different. Colors, patterns, where we find them, how they heat treat... My own experience is that the burlington is in a layer of white clay. There is a vein as well as flintballs running thru the same zone. Finding a creek that cuts thru that zone means easy access to creek sorted flint. This is the best and easiest way to pick up flint in my area, but conditions change from place to place.
If I try to quarry flint from yhe face I work harder and most of what I uncover is freeze fractured leaving me with a lot of waste rock for a lot of effort. Letting the creek sort it for me is much preferable.