HoloDisplays

Stand where you want it, type /holo, click Start from a template, and pick one. It appears above your head, already saved.

Everything about it is then editable from the same menu: its lines, where it is, how it looks, how often it updates, who can see it and what happens when it is clicked.

There is no apply button anywhere in the editor and no screen you can close and lose work in. Each change is written the moment you make it.

Pick it up and move it (or /holo grab) attaches the hologram to your crosshair. Walk backwards and it comes with you; look up and it rises.

The mouse wheel pushes it away and pulls it closer. Sneak toggles snapping to a half-block grid, which is how a row of shop signs gets made level. Right-click puts it down and saves; left-click puts it back exactly where it started.

If your hand is empty, right-click a block rather than the sky - Minecraft sends the server nothing at all when you right-click thin air empty-handed. /holo place and /holo cancel do the same two things from the chat box, and the bar at the bottom of your screen says so while you are holding a hologram.

For fine work, Nudge it moves in fixed steps and saves each one.

A line is a plain string, in the editor and in the file:

lines:
  - "<gold><bold>Welcome"        # text
  - "<gray>Hello %player_name%"  # text with a live value
  - "{anim:beckon}"              # an animation from animations.yml
  - "@item:DIAMOND_SWORD"        # a floating item
  - "@space:0.4"                 # a gap, costing no entity at all

Item lines can capture the exact item you are holding, enchantments, custom model data and all - hold it and press the button.

Colour is parsed after placeholders, so a rank prefix that arrives from another plugin as "&6[VIP]" renders as gold rather than as text.

/holo status answers the only question that matters:

HoloDisplays: 12 holograms, 2 with somebody near, 7 live entities
(0 drawn per player). Loop every 20 ticks - PlaceholderAPI: yes

Live entities is the number to watch. A hologram with nobody near it has none. If it is higher than you expect, look at how many are being drawn per player and at the view range on your busiest signs.

Two settings in config.yml govern the rest and are rarely worth changing: performance.viewer-scan-ticks (how often the plugin works out who is near what - the only part whose cost scales with players x holograms) and performance.keepalive-ticks (how often it checks its entities are still there, because a chunk unloading really does delete them).

config.yml, messages.yml and animations.yml are yours. On an update they only ever gain a key a new version introduced, so your comments and your values both survive.

presets.yml holds the templates, and the editor writes to it when you save one of your own.

holograms.yml is the holograms. The menu rewrites this file whole, so comments in it will not survive - put notes in config.yml. It is safe to hand-edit; run /holo reload afterwards.