I tried making a sugarcane farm which harvests sugarcane once all have grown, but when the sugarcane grows to the observers, they don't power the droppers I placed, but do power them when I break the sugarcane.
I believe this is intended behavior.
The fireball has a "power" tag of a positive Y in your example, and gains a value in other directions in the "direction" tag when hit by a slime block. The "power" tag is the "direction" tag but without resistance, meaning without slowing down.
By the way, I think it being parabolic looks cool.
If you want two observers, try asking in the Minecraft Suggestions subreddit. www.reddit.com/r/minecraftsuggestions
@KingSupernova
No, it happens exactly the same. I didn't press the command block for the Blocks soundtrack, and it could only be made quieter by lowering the master volume.
I recently had this happen to me, but the music piece that played was Blocks, which I played using a command block.
Just found a west facing monument