"My mother had a some ribs and she decided to "help" and pre-boil
the ribs and then freeze them for easy use later."
Back before I knew anything about it, I tried par-boiling ribs prior to grilling them, I had no idea what true BBQ was back then, and I actually thought they were good. All those ribs really were was a vehicle for the sauce, with no flavor of their own. I know better now and I love the 321 method for pork ribs. I use it exclusively these days and meet rave reviews with it, true BBQ ribs never need a sauce in IMHO.
That said on a recent trip to Oregon, (my hometown) I offered to do some ribs for a friend's birthday party, offset smokers are rare in Oregon and I was forced to use a standard two burner natural gas grill which required me to put all the meat on one side and place a pan of chips and can of water over the other burner turned down low to maintain the 225 I was looking for. (Amazingly that setup worked fairly well!) But to my surprise when they brought me the ribs, they were beef, not the pork BBs I was expecting. Still I treated them just like I would have if they had been pork, using my standard rub and mop, doing the 3-2-1 method. They were fantastic! I had also boiled a home cured corned beef and smoked it for the last hour along with the ribs. Both the ribs and "pastrami" disappeared in the first 15 minutes of the party, so I know they were appreciated. Does anyone else use the 3-2-1 method for beef ribs? It seemed to work well, albeit there was a bit of shrinkage I hadn't counted on.