I'm in favor of an individual approach to the topic – how sincerely a person repents/wants to redeem themselves (this already indicates the presence of a concept of honesty – you'll laugh, but not everyone has it, and it may not match yours/the generally accepted one). For example, if, during the process of exposing a cheater, they accused others of unfair play, that's a completely different matter.
Considering reports – you can take them into account, but only to a certain extent. The player in question probably isn't playing for the ranking, but it might be useful for their opponent.