Thanks for the explanation. I will have a look in the next weeks and see, if I am going that route or just wait for the updated images from FairPhone.
Just received info from support:
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I was referred by out department that, technically, Fairphone OS is not supposed to brick because of locking with older security patch. However this hasn’t been tested for the last few updates, so we can’t guarantee it.
If you don’t want to wait for the next update, you can try locking the bootloader and if it does brick, we will cover the costs of the repair exceptionally
The only disadvantage of this is that, if the phone effectively bricks, this entails the fact that you will have to be some time without your Fairphone 4 while it’s getting repaired.
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Not quite sure what I should think about that answer, since we all in the forum and me personally once have already experienced a brick like that.