Describe the feature you have in mind.

Now you may be thinking on seeing this something along the lines of "But it has it's interaction of bonemealing crops when dispensed from a sprinkler right?" yes, it does. This pertains to the actual FLUID liquid fertilizer, the one you can place from a bucket.

Currently, you act like nothing is even there, like the fluid isn't even there! also, nothing happens when contacting lava, though i'm not sure what you'd even do in this situation

All i'll say is, at least give it some fluid interactions

Does this solve a particular problem?

Yes, it makes the liquid fertlilizer fluid, feel like an actual fluid