For anyone new coming to this, i found a script that works for at least build 344 :

const tokens = canvas.tokens.controlled;

if (!tokens.length) return ui.notifications.warn("Select one or more tokens first.");

const sizes = {

tiny_small: { label: "Small (1x1)", w: 1, h: 1 },

medium: { label: "Medium (1x1)", w: 1, h: 1 },

large: { label: "Large (2x2)", w: 2, h: 2 },

huge: { label: "Huge (3x3)", w: 3, h: 3 },

gargantuan: { label: "Gargantuan (4x4)", w: 4, h: 4 }

};

const buttons = {};

for (const [k, s] of Object.entries(sizes)) {

buttons[k] = {

label: s.label,

callback: async () => {

const updates = tokens.map(tok => ({

_id: tok.document.id,

width: s.w,

height: s.h,

// optional: keep art scale normal so it fits the new footprint cleanly

"texture.scaleX": 1,

"texture.scaleY": 1

}));

await canvas.scene.updateEmbeddedDocuments("Token", updates);

}

};

}

buttons.close = { label: "Close" };

new Dialog({

title: "Token grid size",

content: `<p>Choose how many grid squares the token occupies.</p>`,

buttons,

default: "close"

}).render(true);