I joined my team a little less than a year ago. Overall, I think my manager is the best one I've had to date; my prior managers were extremely hands-off and feedback was pretty shallow.
By comparison, my current manager freely dispenses tactical feedback in the moment. He has one-on-ones set up monthly, which are supposed to be more strategic and high-level "how are things going". I've asked for critical feedback every time. In our first one, he gave me minor feedback that has not come up since. Every other one since, though, it's returned as praise and to just keep doing what I'm doing.
I'm obviously not perfect, though. I'd really like more candid, critical feedback; even if I am exceeding expectations for my current role, I could still have areas of improvement in an absolute sense. I've thought about asking about things I think may not be my strong suit, like soft skills, and asking for confirmation. But I don't want to come off as insecure, either, since I could list off a litany of things I have self-doubts on, rational/justified or otherwise. (Also, I'm not sure how to frame said self-doubts if I did.) Is there a good way to really drive home that I would really prefer negative feedback, and push back if it is uniformly positive?