Is it possible to switch to zstd or lz4 initrd/kernel compression for faster boot?

I'm exploring ways to shave a few seconds off of my boot time, and I came across a post that stated, "my initrd is pretty small--doesn’t really load much--and Arch also defaults to using zstd which is also faster to decompress versus gzip."

What compression does Pop! use for initrd and the kernel? When I run ls -al /boot, I see files such as 14M vmlinuz-6.4.6-76060406-generic and 119M initrd.img-6.4.6-76060406-generic. Are these compressed?

Lastly, is there a way to choose the compression of these boot files without a custom kernel build? Or is what I'm trying to do "off the beaten path" and going to lead to "you have to compile your own kernel from here on out"?