Repair broken screen without erasing iPhone to disable find my iPhone?

Erasing the phone is NOT how you disable find my. You remove the device from the list at https://icloud.com/find

Keep in mind that it’s entirely possible the screen has caused the phone to lock (disabled / unavailable) due to incorrect passcode attempts already, which WILL require erasing and restoring to correct. That’s why you should be backing up on a regular basis…

Sorry, but no. You should have a backup that you could use to restore back to the phone, correct?

moritz2282 wrote:

I do have a backup, but that of course does not include esim, banking otp apps, half of wallet and so on. You know how cumbersome it is to restore from a backup.

Additionally the phone broke during a vacation and not all photos are backed up yet.

What would happen if you would connect a new screen without disabling fmi in a third party repair shop? Would that suffice to disable fmi and get the screen swapped again to an oem part?

Bad idea letting anyone else touch your iPhone, unless you would be happy with a 3rd party screen and won't mind if features like Face ID and True tone never work again, plus the phone will forever show that unauthorized parts are installed in the phone and Apple won't likely ever be willing to touch the phone for any service need.

What would happen if you would connect a new screen without disabling fmi in a third party repair shop? Would that suffice to disable fmi and get the screen swapped again to an oem part?

You are asking us to guess. The shop might be able to answer, but I would not trust the answer.

You will very effectively void the warranty.....if any remains on phone......using a third party repair shop.

Expect a message to appear on the phone about an "unknown part" which will not go away. An authorized Apple tech at the Apple Store or an authorized Apple repair shop will very likely refuse to even look at the phone if you require future service.

You let a 3rd party unauthorized shop do anything and you will likely not be able to get Apple to touch it