This whole post really resonated with me. The way in which you invite criticism seems like an excellent way to find hidden flaws, or confirm or deny theories about weak points.

I also try to invite criticism but it's very difficult. Similar to how you mentioned:

" One way of getting better criticism is to come up with a list of things you think you might be doing wrong, then ask specifically about them. This both credibly signals that you’re actually interested in criticism, and also communicates that that topic isn’t one of your weak points. "

I often bring up something I fear I'm doing wrong in casual conversation and explain the steps that I'm planning to take to remedy it. It's a bit of a stealthy way to invite criticism because my colleague will either agree with me and suggest additional steps or will state that they don't agree and add another area that they think would be more helpful to address.

In mentioning a weakness and then directly proceeding to steps to remedy I think I'm able to get over the scary part of the weak point by engaging the solving part of both my brain and my colleagues brain. A negative or weak area is threatening but iterating on a solution is just a problem to solve and optimize.

I also have had some luck in actively asking from criticism from people with little to lose in the situation. Bosses or colleagues during exit interviews, or people who are moving away. Often the transition as well as the feeling that they have less risk in opening up to me can give me some pretty raw feedback. The only problem here is that it's sometimes too raw. I've gotten some pretty brutal feedback after quitting due to the bosses negative feelings about me leaving.