Btrfs installation fails on legacy BIOS systems with first partition aligned to sector 63

[geckolinux]

With vanilla Debian and SpiralLinux, GRUB installations to the MBR (legacy BIOS) with a Btrfs / will fail on some older systems that have the first partition aligned to sector 63 (usually ones that came preinstalled with an old version of Windows) due to the core.img being too large (because of Zstd support) to fit in the space before the first partition. The scenario is presented more clearly here:
https://bbs.archlinux.org/viewtopic.php?pid=1285315#p1285315

grub-install --recheck /dev/sda
/usr/bin/grub-bios-setup: warning: your core.img is unusually large.  It won't fit in the embedding area.
/usr/bin/grub-bios-setup: error: filesystem `btrfs' doesn't support blocklists.

The workaround is to not use Btrfs for this sort of installation or re-align the start sector of the first partition.