I think that's an excellent idea, especially for people who have pleaded guilty. I was referring earlier to the Simon Marshall case, but I'd also like to come back to some decisions involving indigenous women. In the case involving Ms. Lavallee, the battered woman defence was upheld. Often, a person can state that they are guilty of killing their spouse, but in law, that homicide is not illegal because it was a case of self-defence. However, the person may feel guilty inwardly, and if they don't have adequate representation, they may plead guilty. They won't be tempted to appeal.
It's complicated to appeal after a guilty plea, since you have to withdraw the plea first. Especially in cases of guilty pleas, the idea of exhausting remedies is not the right solution. Even if there are fewer miscarriages of justice in guilty plea cases, that doesn't mean there aren't any at all. The Marshall case is a very good example. I'm thinking in particular of vulnerable and marginalized groups. They may be a little more inclined to plead guilty because they fear what might happen if they don't, or because they don't understand the legal standards.
Sometimes, a person may feel very guilty when, legally, they are not. We can think of cases where the person suffers from a mental disorder. They may feel guilty, but they could mount a defence based on mental disorder at the time of the act.