Will /e/ use a custom key for verified boot/secure boot on the Fairphone 4?

Dear Community,

recently it was confirmed that /e/ would be ported to the Fairphone 4 here:

It was confirmed by the Fairphone Support that the Fairphone 4 will support custom keys for verified boot/secure boot. Source:
https://forum.fairphone.com/t/psa-the-fairphone-4-does-support-verified-boot-secure-boot-with-a-custom-key/77547

I would like to know whether /e/ takes the security and privacy of their users seriously and will implement a custom key for verified boot/secure boot?

Will it be installed, or shall we have to install it ourselves. From a ordinary people user…

Easy
On the so called Murena phones it will be pre-installed. otherwise not and you have to do it for your own.

What exactly is this custom key?

hmm … the OP link seems to be broken! I think it actually pointed to this topic:

Careful searching of links from the “Solution” will explain Custom key in context!

Thank you for this explanation aibd