A key method in reducing false violations in HLDRC is to ensure that the rule's parameters are set appropriately for the task at hand.
Using the rule documentation to review the rule’s theory along with the explanation of Perquisites and Parameters is a must.
Each rule Documentation also has link found at the bottom of the first page refer to as Violation Condition this will brings you to the rules flow algorithm.
There are also great videos found on each of the rules in Support Center (which you should have access too)
Finally if none of the above help please provide more details on a specific issue, it would be useful to include a picture of a false violation and why you feel it is so.
One thing you did mention that I do not fully understand is the is issue with diff impedance rule calculation concerning arc turns and right angle
Can you provide more details?
Thanks for using HyperLynx DRC and keep in mind this is right place to get assistance along with Support Center.