If on the same net DRC, due to the stack via design. Alot of DRC will apply also.
Is there a way to identify this issue? Pls advice.
This is exactly the type of issue that I am trying to address - duplicate drills with the exact same xy and touching drills and then create a report file for them. Fab shops desire the report file so they can modify the NC drill file so not to make double or more hits on a single hole. Is it possible for you to expand on your code slightly to create a simple report file? The duplicate drills are also counted in the drill legend, but that is another issue.