Hi @floji !
From Toradex side, I was informed that no extra effort was made to test/support U-Boot’s splash screen feature.
Although it is possible that the upstream project made some advances in that front, from Toradex side it remains in the same state.
If you wanna share what specifically you saw that was interesting, I can take a look as well 
How is it on your side? Is this a decisive requirement for you?
We could introduce you to some of our Toradex Partners that could help you on your specific implementation need for splash screen on U-Boot.
Best regards,