Just how magic are they ? All my devices are chinese knock offs, most of them with the ' magic lock' that is so magic i can pick it with a paperclip in a few seconds. I am no expert picker, its just that they are useless. i have both the ones that come with a V3 and a V4, different keys but both so easy to open. Is it possible to get a secure one.? I have actually taken a 6mm drill to mine and use a drilled stainless bolt and a padlock, but while it is quite secure its also a bit clumsy, a decent magic lock would be better, certainly for steel devices ( I find a through bolt better for anything made of thermo plastic resin as they tend to open up across the lock area and become insecure and loose after a few hours wear.)
There is only one quality maker which is Burg Wachter from Germany. Buy one and throw the Chinese ones in the garbage. https://www.amazon.com/dp/B07P6HQV5T/ref=cm_sw_em_r_mt_dp_ARCXJF9GK2MMXKMFX3M1
I picked the Burg Wachter just as fast. Only solutions for us were: 1) Nail polish painted over lock, 2) Drill hole and fasten numbered security seal. Thus I think security screws (Licktighted) are the best.
The simple fact is that no lock small enough to be used for a chastity device is going to be very resistant to picking. Why would a manufacturer invest the time/money in designing/producing a pick resistant lock that could so be easily cut off? If you can find a device to accept it and your genitals can stand the weight.