Barry,
I have tried 50% pulse from a 6A base but I didn't feel much difference from 30% from a 7A base. If you would like to try it and let us know that would be great. To get the most useful data I always like to compare any charge method against a regular 5A linear charge done on the same cells running about 4 cycles of each running alternate cycles, i settled on what I'm doing now as I'm getting good data 4350 Mah in on charge with 3700's and well equalized cells.
Chris