Is there any way to modify the grub-install command in ArcoLinux calamares installer?

I need to append --removable to the grub-install command to actually install Grub. Is there any way to do that in a graphical installer such as ArcoLinux calamares? I tried editing the bootloader.conf and change grub-install line there to include --removable, but that just says that no such file or directory exists. Install log: https://termbin.com/xwz1 without editing the grub-install command.
https://termbin.com/p5cf with --removable

In bootloader.conf, grubInstall section:
grubInstall: "grub-install --removable"

I don't know what to do. Can anyone help me?