if you're only a few feet up just maintain 0~3 degrees pitch or so and let it ooz itself in. A high speed descent is required when you're high up because it's the only way of coming down to a few feet high without loosing head speed, or when you have a low rpm to start with. Many larger helis can come straight down (level), and not very fast, at -2 degrees pitch or so and actually speed up the blades you can hear the whooshing sound of it and be comfortable knowing there's plenty to expend. I must admit I haven't experimented this with these little e-birds tho the blades are less audible and a blur dot high up there, so it would be safest to give it 0~-1 degrees pitch and dive right in as fast as possible to preserve rpm plus you can also pull cyclic at the foot in addition to relying on collective alone.

Clement