Just picking your highest elo instead of your current elo doesnt fix smurfing at all. It will pretty much make match making much worse.
This alraedy has the solution against limiting smurfs on the TG ladder. I dont feel the need to express myself any further about the fix for the rating. Just read that thread about all the ideas to tackle all the issues on the TG Rating (where smurfing is a real issue).
Next to a better rating system i suggest better moderation, with an auto flagging system based on some rules. It also looks like you can report smurfs, but looks like there is no moderation on this at all by the devs currently. They probably agree that the system is pretty much exploitable, which promote smurfing. There are too much smurfs to handle for them. First priority should be a better rating system (see above) and then add some better moderation system.
Just some ideas of possible rules:
- more then x losses in a row
- more then x wins in a row
- more then x games within a certain time frame
These will already flag a lot of smurf accounts. There will be some false positives, but since the list isnt auto banned, but looked at by the dev teams, this should be no issue at all. The dev teams should see it is a false positive and just do nothing with such account.