..which might become a valuable token in the future just like BNB ?
I doubt you will have a concrete answer for that.
I want to experiment by investing into a exchange token when it's value is less as it might give a good amount profit. I am sure those who invested into BNB at it's early stage got my point.
BNB development was done in a serious approach that's why it created a positive rating for the investors. And we all know how wonderful the crypto market is during 2017 where BNB ICO held and that also contributes to their success and achieving good funding.
I suggest to list down all exchange with their own token and study their past performance and from there make your own analyzation. It's risky to just follow anyone's suggestion because their point of view is based on their own preference. After analyzing, now time to test the waters and accept the risks.