Hey,

I've seen some plugins lately adding support for hiding holograms too far away from the player.
Would this be possible to implement? Or is this already possible?

Sorry for the late answer. It would need to be implemented with Protocol Lib, but is there any reason to? Holograms aren't probably a cause of FPS drops client side.

It would be nice if it's optional for users with Protocol Lib.
The reason wouldn't be for FPS, but it looks way more neat then holograms thru all the walls and buildings in a distance.

In spigot.yml you can change the tracking range of these two to achieve the effect:

world-settings:
  default:
    entity-tracking-range:
      misc: 10
      other: 10

Implementing it in Protocol Lib is difficult and time consuming compared to the improvements of this feature.

While that indeed works, that setting applies to more then just holograms. It's not the best solution and i'm not a fan of it myself. Hoped it was possible to add with protocollib support just like CMI did it with their holograms.