I'll have to say, safety wise, if a punter wants to abuse the girl, there's nothing an agency can do until afterwards. However, the operation of Ginza definitely allows safety for girls as the receptionist is always a door away.

Importantly for girls is having a moral boss whom doesn't lie; eg saying: I know this customer so well, you should serve him, even though he only called the first time.
Or refusing girls to change boats with threats
and many other little things that might come with any agency.

On the other note, having a driver to sort this out might even be safer as my understanding with MOC's driver (don't think they even drive every girl to destination) doesn't just sit outside the door waiting for her to finish.
I've met a nice freelance driver(Big LEB guy) before whom only charges 30 per hour for his services to girls. Then again, he has a side business running also.
Honestly, A driver is much more effective for safety and much cheaper. Advantage of MOC for tiny at this point is that they've got a massive client base.

At the end of the day, she's chosen and we should just wish her all the best.