I do not see the iPhone 12 Mini listed here: https://dl.djicdn.com/downloads/DJI_OM_5/DJI_OM_5_Mobile_Phone_Compatibility_List_en.pdf

Does that mean it definitely doesn't work?

Thanks.

I believe it will work.
I have samsung note 10 plus. And it works even it doesnt in the compatible list.

Hello there SkipMc. Good day and thank you for the inquiry. I hope that our fellow DJI Members who owns the DJI OM 5 and uses the said mobile device ( iPhone 12 Mini ) can give out the best recommendation with regards to this matter. Just a reminder that DJI recommends using a recommended mobile device on the DJI OM 5 for compatibility and reliability on both the said DJI gimbal and for the DJI Mimo application. Thank you.

It works but not as good as (I believe) with other iPhones - the ones on the compatibility list. Primarily the DJI Mimo app doesn't fit the screen of 12 Mini, so some elements are only barely accessible - they are "out of the screen" with their bigger part. Blutooth connection is not easy to establish after resume, so I have to try few times before I can start filming.