I dont wear any safety gear, because (1) I dont speed, (2) I know and feel my board enough to be safe, (3) monitor battery and dont ride below 10-15%, (4) I can roll/run it out if anything happens.
but newbie riders should at least wear a helmet, and install fangs to protect themselves from nosediving. These are a must, I would say
Most nosedives happen at around 19-20 mph, I usually dont drive faster than 13-15.
Also depends on the weight, if you are tall&heavy, you should drive even slower.
Also nosedives happen if you just plain accelerate on flat ground with flat stance, I prefer to “carve” and alternate weight between sides of the wheel. That way you can decrease power required to move (because of decreased contact area and decreased rolling resistance)