It is way slow and definitely not practical to use for normal day to day photography...I have started using app called brightly where I process pictures at my convenience as and when needed.
Does what it says! I don’t have a Google Pixel to compare the results with but so far the shots look way better than the stock XS Max camera app.
Worth the $2.99 I’ve just spent. I hope you optimize the algorithms even more in future to reduce the waiting time.