The worst way you can welcome a new thing a colleague has worked on – something that fills a gap, something that was needed and was not there – is to say: “Can you also do this?”.
Of course, it’s imperfect. It’s the first time you have that.
Of course, you have ideas and opinions. You were given time to think about it.
Of course, it will get better. That’s probably also why they have shared it.
“Can you also do this?” is the surest way to have the colleague stop working on it. Welcome the novelty instead, the initiative, the boldness. And give the new thing time to develop and accept your vision.