Is this a good way of using functions in metatables?

Hello, i mostly know how metatables work, although i don't know if when making a module, is this a good way to store __index function?

local module = {
	__newindex = function(a1, a2, a3) -- The function is stored in table, that is returned
		print(a1[1], a2)
	end
}

function module.CreateSetup()
	local statsToReplicate = {}
	
	return setmetatable(statsToReplicate, module)
end

or should i create it like this, store the function in seperate table:

local module = {}

local metatable = {
	__newindex = function(a1, a2, a3)
		print(a1[1], a2)
	end
}

...
return setmetatable(statsToReplicate, metatable)

Thanks, kirda