Graft-Kernel
graft-kernel is a stanadlone UKI generator with the same featureset as systemd-ukify.
Unlike systemd-ukify, it allows defining a custom path to the PCR measurment utility, allowing the usage of gardenlock-measure.
Source
Graft-Kernel can be downloaded from https://git.pinkro.se/Rose/gardenhouse/graft-kernel.git/about/
It's also mirrored to Codeberg where bugtracking is done.
A sys-kernel/graft-kernel port is available in the Gardenhouse portage overlay