Some cheaters like Soyd are just complete faggots who ruin everything for everyone and ban evade on 5000 accounts just to waste the staff team's time. But some people that cheated once and didn't bother ban evading or anything I am almost certain regret it, otherwise if their intention was to ruin people's time I'm sure they would just continue to ban evade and attempt to cheat again and again. Personally I feel like it would be fair to wipe their character completely and unban them (case by case only) if they were "approved" to be unbanned. I don't know, maybe 2-3 years since their cheating ban and no attempt to evade the ban seems fair so that people don't just cheat now because they know they can be unbanned within a short amount of time (2-3 years is quite a bit imo).
Sadly though cheating here holds a heavy punishment here and I don't think we'll be seeing anyone unbanned any time soon. Real shame really because some of those people were nice players, but you just can't be certain that they won't cheat again.
But aside from cheaters, I think real permanent bans are kind of silly, 12 months is more than enough for someone to learn from their mistakes (assuming we are talking about rule breakages here)