Flatpak and icon themes

I noticed that the programs I installed with Flatpak do not use the right cursor theme, so my initial solution was to copy the Adwaita icon theme from /nix/store to ~/.icons which worked.

But I found out that the icons themes get symlinked to /run/current-system/sw/share/icons so I symlinked it to ~/.icons:

lrwxrwxrwx 1 broccoli users 35 14. led 23.10 .icons -> /run/current-system/sw/share/icons/

However this does not work, and I suspect that it is because the actual icon theme is owned by the root, can I chown it for my user, will I break anything? Or can I just change the owner group to users instead?

No, it’s because if flatpacks security model, which forbids reads outside of its sandbox, and the nix store, or some intermediate link is probably not readable for the flatpack.