Yes, this is a good question. I just checked the online system and I'm eligible to apply under the express entry program. Now, considering the overstay history, I would like to know should I proceed or not. The previous answers provided some insight that it should not be a lot of problem when someone is truthful about their immigration history.
However, is that explicitly asked in the PR application about previous overstay in Canada or another country ? I know people who get Canadian student visa with previous overstay in US, but, I imagine for the PR they might have tight rules.