This is a test build. It passes all editor checks but has not been seen in a real mission yet; the ring may not render, or may stay behind in some situation. If something goes wrong, disable it and let me know.
The Shield Link perk's passive effect makes teammates within 4 m regenerate shields faster. The game never shows where those 4 m are, so almost nobody knows whether they are in range, and the perk is rarely picked.
Shield Link Range draws a 4 m ring on the ground around every dwarf who has Shield Link (teammates and you). Walk into the ring to get the buff; the ring brightens while you are linked.
Who gets a ring: every dwarf with Shield Link equipped, including you. Whether a teammate has it is data the game already sends to every player, so the host does not need this mod.
Ring size: read from the perk's own range setting in the game (currently 4 m = 400 units), so it follows any future balance change.
Bright / faint: brighter while the Shield Link effect is on you and you are near that dwarf (a hint, not exact link data: the game does not tell clients who is linked to whom). Faint while that dwarf is down, because a downed dwarf links nobody.
Terrain scanner: the ring hides while you hold the scanner (Tab) so it never covers the map.
Settings page: a "Shield Link Range" page in the Mod Hub or Unified UI menu: on/off, show for Everyone / Teammates only / Only me, language. Changes apply immediately and are saved.
What it doesn't do
It sends nothing to the host and changes nobody's game; it only draws on your own screen.
The ring is flat: the game measures 3D distance, so on slopes and between levels the real range is a little smaller than the ring suggests.
It does not draw who is linked to whom; the game does not give clients that information.
How it works
Shield Link attaches a component (ShieldLinkComponent) to the dwarf, and the game replicates that component to every player. This mod just finds dwarves with that component and puts a ring-textured plane at their feet.
It is separate from Ally Outlines Plus and can be installed alongside it; each has its own settings page.
Install
Fully close the game.
Download ShieldLinkRange-0.1.0-alpha.1.pak, add it to your mod manager (MintCat) and enable it.
For the settings page you need Mod Hub or Unified UI (without them it still works with the defaults: on, everyone).
Play as usual. To adjust it, open the mod menu (Unified UI: B by default, Mod Hub: H) and find the "Shield Link Range" page.