Wrote you a small book in PM.
For anyone wanting to learn about one of our friends look up Neoseiulus (Amblyseius) californicus.
That is an untrue statement. There are multiple sprays that kill them dead. There is however nothing that can be sprayed in flower that is safe for consumption, so plants need to be revegged back out to take new cuts. There are also about 5 natural predator mites that eat them and several flying insects that will. You just have to know what can be used together so that one bug is not eating the other.
FWIW the hardest thing about broadmites is knowing you have them. After that they ain’t shit.