BASE jumpers commonly expect their canopies to be loaded very, very lightly. But they jump 7-cells with low aspect ratios (i.e. how tall the cells are as compared with the width). Lots of room for the air to rush in.
You can end up going backwards in lower winds than other people; of course, you'll still be way better than people used to be jumping rounds 40 years ago. Trust me on this -- I jumped rounds for a long time, as well as more than one low aspect ratio 7-cells loaded at under .7.
When you load in the .3 (or lower) range the canopy actually stops functioning as an air foil, there simply isn't enough weight to create enough airflow. Pulling the toggles may give a minor amount of heading control, but for all practical purposes you're under a funny shaped round.