Its by far not a Solution for the Whole thing. But maybe a little step into the right direction.

I noticed (and many others too) that wintrading players often decline the invite when theyr Wintrading partners dont get invites too to avoid honest playing people.

So in another MMO (not sure if im allowed to mention it here) a declined !Rated! PvP match immediatly counts as a loss and lowers your Ranking. When i was playing soloqueue in the Early morning hours i sometimes had 3 declines in a row after getting the invite window popping. So that would have counted as 3 losses for those people. Maybe that would be a step forward to give those cheaters a little Wall to walk into.

I for myself stoped playing rated for the moment. It just feels pointless especially when i see people on the top 100 that clearly dont belong there and it gets even worse since SE isnt really doing anything against it wich encourages even more players to do it.

Just my 2 cents.

Have a nice Day.