The large popup window which shows up when I navigated to the website is quite intrusive. I would suggest making this more user friendly.
No, it's not. It opens instantly, has no close timer, is very obvious about its intent (which is beneficial to the user), and closes instantly with a single click (and stays closed on subsequent visits). It's minimally intrusive at best, but the trade-off of the very relevant user notification negates even that.
> There are other, less obnoxious ways to ask for feedback
Yes I agree but I don't think that applies to this specific use case.