With success and with failure. Attitude on appeal says a lot. Not all permabans may be equal either. Mistakes of childhood, bad situation vs very specific irredeemable circumstances. I'm more confident if I see true reform in an adjacent community. If I see the same crap in a different place then the response to appeal is 'go away'. Either way the otus is on you to demonstrate change, not to say it, and preferably somewhere else. Eventually you might have to ignore tragic appealers (generally in a broader community) who appeal again and again and after countless explanations they never get it.
This corresponds with 'sneaking back in'. On one hand that's evasion and blows away your case. On the other hand if the return is absent of the issues that resulted in permaban and I never notice, I guess that's a win. If I do connect the dots, there is no issue and I would consider an appeal, I might just respect the fresh start. But that's a dangerous game and more than not it's blown very quickly, along with it any chance of appeal.
Then there's this one dude who has been trying over a decade on one board. Long into the 'ignore/go away' stage, obviously...