"It shouldn't be that hard" -Famous lasts words.
I'm gonna leave a message here because I always wanted something like this, it was already done on the Wii version apparently, and I think it was also promised for Toribash next but it's not present in the game currently.
For them to do so they have to rework entirely how the blood works and behaves I think, and honestly I'd be happy if they did a rework on how the blood works, it could provide a way better immersion because currently, blood also goes trough any rigidbodies except the floor, which is static and plain, therefore easy to process.
Now they added item effects so either the devs are experimenting more with shaders or they are making it harder to implement blood effects.
*Also, I would love to see more reactive blood instead of just collision effects that are spawned and instantly go downwards*, blood effects during collisions never sounded reasonable to me unless it was because of dismemberments or very hard collisions, or rigidbodies that can trigger blood (for mods that incorporate knives for example)