See I've not had issues (yet) - but had issues years ago. I swear like clockwork; I'd go to MG at wallyworld and do my part, leave and within an hour get a call asking questions and than stating to pick up my funds as it's denied. I'd go to WU and no issues. Drove me insane. I might have found some reasons behind it and I really believe often times it's with the teller you're handing the paper and cash to. I do not and have not been asked for an ID anytime it's gone through with either operation. I do not use Wallyworld at all (there's maybe 2 in my city), I use CE's instead. For safety I feel it's best I don't say too much out in the open though and I apologize for that, it defeats the purpose of posting.
Send small orders, frequency has yet to be an issue for me. I'm rather frequent to say the least. I send to one place period. I bring up the teller part because my teller has asked me "Have you sent to this person before?", as she's entering the MG info into the computer. It's all she asks, unless I misspell a name and she tells me to double check because she doesn't think I'm spelling it right (she's always correct lol). Which that saves me a HUGE headache later. Again, reasons why I feel it may a bit part the teller and not always "flagging".
Do people get flagged? OF COURSE. Usually it's for X amount of days 7-365, normally a few weeks. there's also a limit per month on what you CAN send to certain places. I have been told by Mg the limit to the country I send to is 2k per month, anything over that is flagged and you cannot send. Here's where they get you: I had an order years ago where I sent it, receiver was flagged and I had to show my ID (standard) to pick up my funds per refund. I went the next day to send to a new receiver and because they COUNT refunds towards this 2k, I couldn't send again for 30 days. Both refunds & sending apparently go towards this limit.
I hope there's some info in here to use - sorry for the rambling! Too much coffee today