Thanks Iņigo and Gertjan,
Rebuilding the kernel without the animation seems doable, but changing the bootloader setup sounds a bit risky to experiment with.
I did poke around a bit though. If I'm correct the DR uses RedBoot as a bootloader and /dev/mtd2 as the location to store the Redboot config. If I dd /dev/mtd2 I get something like:
delta erase 15
ifwarm fis load kernel
ifwarm exec -c "console=ttymxc0 deltainit=1 root=/dev/mtdblock5 rootfstype=jffs2"
fis load kernel_recovery
exec -c "console=ttymxc0 deltainit=1"
I'm guessing one would have to remove "delta image" and "delta erase 15" to start without the splash screen? I have no idea how to do this safely though.
Edit: I tried editing the Redboot config using dd, but it seems to be read-only...