Figma helper to toggle layer ordering using 180 hack to match z-index of web

toggleLayerZIndexOrdering.js

function reverseChildren(children) {
	const length = children.length
	
	for (let i = 0; i < length; i++) {
		var oppIndex = length - i
		children[i].parent.insertChild(oppIndex, children[i])
	}
}

function toggleLayerZindexOrdering(node) {
	if (node.rotation === 0) node.rotation = 180
	else if (node.rotation === 180) node.rotation = 0
	const length = node.children.length
	for (let i = 0; i < length; i++) {
		var child = node.children[i]
		if (child.rotation === 0) child.rotation = 180
		else if (child.rotation === 180) child.rotation = 0
	}
	if (node.rotation === 180) {
		node.x = node.x + node.width
	node.y = node.y + node.height
	}
	else if (node.rotation === 0) {
		node.x = node.x - node.width
	node.y = node.y - node.height
	}
	reverseChildren(node.children)
}

toggleLayerZindexOrdering(figma.currentPage.selection[0])