Yes, you can. I really don't want to be in the business of building OSes. If these guys make it so that getting reasonable boot security is a simple toggle, I'd be grateful.
Then there is also `ukify` by systemd which also can create UKIs, which then can be installed with `kernel-install`, but that is a bit more work to set up than for `mkinitcpio`.
The main part is the signing, which I usually have `sbctl` handle.