I remember seeing in an interview with Benjamin Bloemendaal, Vekoma's senior designer that the vests are optional, Vekoma use them as a default. However a park can ask for just the lapbar if they wish.The best bit is that it appears there’s no vests on the STC trains.
Even the seatbelt isn't necessary.a lapbar in combination with a seat belt is very safe and allows smaller kids to ride too!
^The park have said they expect them to open during Spring time. However no exact date will be announced until closer to the time.