Here's the list of compatible laptops:

https://libreboot.org/docs/hcl/index.html#supported_laptops_...

Nothing recent but on the plus side, you should be able to pick one up without spending too much.

Chromebook C201 is very recent (currently sold new), supercheap (<$200), and can run not only Libreboot, but completely blob-free. Not even CPU microcode is needed.

Is it possible to put bigger hard drive in it? 16GB is very limiting.

apparently, it has an eMMC soldered to the motherboard instead of a HDD/SSD...

Do you need a binary blob to run the RockChip GPU though?

You get full 2D from the Linux kernel, but yeah the 3D GPU is Mali, so no luck if you need OpenGL (in hardware).

Unlike the ME/PSP situation (signed binaries for a coprocessor that decide whether to turn on your CPU) this can be fixed with enough effort and grit.

I put libreboot on an old 2006-era X60s, and it wasn't too much trouble once I'd worked out which instructions to follow and which ROM to use (which was not obvious). That appears to be the best supported laptop, and you can pick them up very cheaply on EBay.

Picture: https://rwmj.wordpress.com/2016/04/10/libreboot-on-my-x60s/

You're better off using coreboot, libreboot is just a set of patches removing non-libre boards and microcode support.