Using grub-coreboot instead of grub

I have problems booting trisquel with Libreboot (202107) on X200 and T400 (it eventually boots but see details at the end) and on #gnuboot, it was reported the same problems occur with gnuboot, and it was advised to try using grub-coreboot instead of grub.

Would the following method work to do that:
- sudo apt remove grub
- sudo apt install grub-coreboot
- sudo grub-install /dev/sda
- sudo grub-mkconfig -o /boot/grub/grub.cfg
- update-initramfs -a
?

The details:
- after asking to boot from the initial GNU boot/Libreboot menu, the time until getting the graphical screen and the box to type the cryptsetup password comes is random, it can be a few seconds but it can also be more than two minutes.
- in that last case, a graphical screen appears but no box to enter the cryptsetup password, the Trisquel sign is breathing for a while and nothing happens for some more time. If I wait long enough, there may be an input box that finally appears but then, the computer will not be able to shut down unless by a long press on the power button.
- the same problem occurs when selecting seabios instead of grub in libreboot
- the problem
- the problem does not occur with parabola (and it was not noticed by anyone using guix sd)