Is it appropriate to ask journal review status after not hearing back in quoted timeline? I submitted a paper to a journal three months ago and was told that the review process could take up to three months but that they aimed to do it faster.

Since I haven't heard back within the quoted timeline, would it be appropriate to contact them and ask how the process is going?

On one hand, I could see that they may be very busy and have received more submissions than they anticipated.

However, I also wonder about the possibility that something has slipped through the cracks - like perhaps the review is over and they lost my contact info or something.

What's the appropriate action to take?

The journal is free to submit to, free to read, so I know that folks aren't getting paid, which makes it harder to expect the timeline to be met, but I'd still like to make sure things are on track.

Thanks!
As a sometime-editor, I wouldn't be offended by such an email. Not happy, but not offended. I'd say go ahead and email.

(My first editing stint significantly increased how fast I turn around peer reviews...)