Last time I checked there were about 20% smurfs in silver ; but due to the randomness of the matchmaking it’s completely possible one momentarily faces more than that. 
I do agree on the principle of increasing the queuing time for freelosers though, it’s a suggestion that wouldn’t hurt regular players, and that would be relatively easy to implement. The only detail is to set an adequate cutoff regarding freeloses detection.
It’s already been proposed on the big thread btw, there are a couple of variants in part IV (just type ctrl+F twice, then “IV -” . If you think addressing this is important for the game, then leave your thoughts there as well, it’ll help. 
Increasing queue times rather than “bans” I’d say. One user suggested the queue time penalty would be 5’, then would double with each freelose in a defined amount of time. Meaning if you freelose 5 times, your queue time before laddering would become 1h20 minutes. 
2v2 smurfing can take different forms, however. And not sure what you mean by family support though.