With the package [linux-aarch64-chromebook] 5.11.4-1 the vmlinux.kpart file is too large, so that it does not fit on the (32MB) partition and thus can't be booted.
Currently only linux-gru can boot on on bob (ASUS Chromebook Flip C101PA) and kevin (Samsung Chromebook Plus).
With [linux-aarch64-rc-chromebook] 5.12.rc3-3 vmlinux.kpart has a small enough size, but the screen sadly stays black on (at least on bob).