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

If you are using automated ones, set the swinging to the lowest to minimise the motion. Generally, normal usage of automatic swinging will not affect their brain unless they falls out of the cradle mid swing. If you are using the traditional sarong cradle, it will be good to always keep an eye on baby and do not use it during night time as we are not so alert at night. My baby fell out from the cradle once and we never let him use it ever again as it is quite traumatic to us not just baby. We are not using the automated ones and lucky that we had put a mattress under the cradle to prevent such incidents.