Is it true that using the automatic swinging yao lan (sarong) can cause damage to the baby brain due to constant swinging motion?

My both kids used yaolan till 1 year old. We just rock it gently and stop rocking after baby has fall asleep. We took precautions such as placing a small mattress below the yaolan, put yaolan in living room where visible to everyone, and refrain from putting toys/pillow inside yaolan with baby. As long as there is supervision during the usage, you can prevent baby from falling out from yaolan. It will not cause brain damage if you rock it gently. I would recommend manual one instead.