I have the WeChat and/or Instagram of several Korean and Japanese traveling girls that visited Montreal. With a few of them I spent (unpaid, mostly social) time privately after they wrapped up their time with the agency or, if they were coming back to Montreal, before they started working. I don't see anything wrong with it.
I sometimes see girls at Euphoria or Forever, but I wouldn't ask for their details. I might be ok with exchanging if they asked, not sure, depends I guess, hasn't happened. But the risk of them becoming annoying in some way or another is much higher since they're local. I prefer to keep a professional distance and have contact with local girls only through an agency.