There are two issues;
1. Somebody who cheats (and who deserves to lose their points)
2. Somebody who is wrongly accussed of cheating
So, if somebody cheats, then as the suggestion goes, they should be 'deadbeated' from their active games:
- "xxxx is kicked out for being a multi"
This way, that player would lose points, rather than be allowed to continue to scam the innocent party.
For a perpetual cheater, a score reset happens, which doesn't affect the scores of any previous opponents.
If it transpires that the accused is innocent, then presumably they would be able to have points added on in a similar manner to the points reset? If this is the case, then it should be possible to do a search for games where the accused was 'kicked out for being a multi' and add on the total lost..?