[fweespeech]

Why?

Its a deal that ends the legal proceeding permanently.

[brazzledazzle]

Perhaps this is an exception to it, but what if information comes to light that completely invalidates their case and proves that you're innocent?

[fweespeech]

You've admitted guilt with full knowledge of the legal consequences, while advised by an attorney [unless you self-represent and fire your public defender].

I'd say its the one situation where, yes, it isn't going to be 100% perfect but trying to "improve" it will likely have collateral damage.