UI Automation and testing Сanvas, TextBlock, etc.

Question

Software testing

There is a great desire to automate application testing. The main functionality of which is working with WPF Canvas. On which “schemes” are drawn (rectangles, lines, points, more complex composite geometric shapes). On the “schemes”, you can highlight / see elements, call the context menu, etc. The question is how to achieve such testing if Canvas does not initially have AutomationPeer.
There was a similar issue with TextBlock test automation where it would not return its text content if the TextBlock was used inside a DataTemplate. But it ended up like this .
There is an idea to promote something similar for Canvas (that is, add your own Peer by overriding the existing implementation of Canvas). But maybe there is something simpler, and without interfering with the fragile legacy code?
Share your thoughts, practices, how to automate UI testing, if anyone met?
Is UI Automation only suitable for simple cases?
PS write down the coordinates and poke the mouse - can lead to a fragile test. Yes, and I also want the reverse scenario, to find the coordinates on the conve by the Id of the element ...