You're need to know the only one reason why user get permanent banned is due to plagiarism (most case) or spreading malicious link, if he never plagiarism other people post with his main account, his alt wouldn't get banned due to ban evasion. AFAIK spamming will only get punishment for temporary ban, although there's a permanent ban for spamming but it's rare to happen or maybe no one.

Cheating doesn't have any relation with ban punishment.