Frankly, as Apple is now explaining why they included mouse support, I'm a bit disappointed. They continue to belligerently tell you how to use your very expensive iPad, and why you basically should be happy with touch, as it's a touch device primarily, and only handicapped need to use a mouse (or should). And how they understand (understand), how there will be some oddballs who actually don't want to use what they tell us to use, but hey? That's our fans for you!
Not simply: Use both.
The mind boggles, and this is EXACTLY what I thought was going on.
End rant
What Apple has to say -
https://9to5mac.com/2019/06/06/using-a-mouse-with-an-ipad/