You can vote for the relevant feature request here:
https://forum.fairphone.com/t/fp-os-os-feature-requests-vote-for-your-favorites/12303?u=johannes
Fairphone aims to be as open as possible in what they are doing (but there are some limitations). Being open does entail breaking the security model of an operating system, or providing all the features that every user may want. For the OS they provide, they make as much of the source code as possible available so that you could in theory make changes. They also facilitate as much as possible the option of installing other operating systems. It’s early days, so the latter will take a while to work. Meanwhile discussion about the source code for Fairphone OS, and how to compile it are here: