This is not a duplicate of I'm out of close votes. Can I use moderator flags instead? because that is a support question asking if one can use moderator attention flags to indicate that questions should be closed. This is a feature request asking for the ability to use recommend closure flags (which feed questions into close review, and don't go to moderators) when one is out of close votes.
Currently, flagging for closure is treated the same as casting a close vote for users with the vote-to-close privilege. From what I can see, this is basically for users' convenience - if I think the question should be closed, there's hardly ever a reason not to cast a vote if I can.
I cannot see however why I cannot still use a flag to nominate the question for close review - since this won't include casting a vote - same as if I didn't have the privilege.
This goes for all close reasons, including suggesting a duplicate.
If a vote creates a review item, why not consume both a flag and a vote? This will mitigate the cumulative effect referred to in Robert Longson's answer and is quite logical: flags are used to create review items while votes to vote on them.
It's also very strange that users with <3,000 reputation can add dozens, if not up to 100, questions to the close vote queue (provided their flagging history is excellent, and this number can increase quickly since a single close vote results in the flag being marked helpful), but when a user earns 3,000 rep, they're all of a sudden limited to adding only 24 questions to the queue.
Related discussions:
- I'm out of close votes. Can I use moderator flags instead? (considered flagging for moderator attention instead which is obviously a no-go)
- Allow marking questions as duplicate even when out of close votes
- Should flagging a question for closure prevent close-voting?
- Allow me to flag to close even if I already used my close vote