How to control "Same net spacing" constraint rule value of overlap rate?

I believe there is a misconception in the industry about acid traps.  Experts such as Lee Richey have been stating that Acid Traps have not been an issue since the early 2000's.  I would recommend a conversation with you fab house to double check this.

See here for an article on this and the 90 degree bends (Taken from "Right the first time" - great read), Speeding Edge.  I also believe I have seen this topic discussed in Dr. Howard's tutorials.

More info here: https://resources.altium.com/p/slaying-900-right-angle-bend-dragon

I know it's an altium_crap site, but good information can also come from the "dark side:

Well, some of my design have required/expected life more than 30 year in uncontroled environment. Some of them are for security. I can not have a  risk with acid still eating copper. And avoideing acid traps is verry easy.

When I stared my carer at Bell Labs in 1986, we saw issues with acid traps, so I am not denying that this was a problem.  However in the late 190's - early 2000's the manufacturers that (Lucent Power Systems) we used never had issues.  This was alluded to in the articles I referenced.  I am not saying that it is not good practice to avoid the sharp corners, but rather I suggest that users talk with their fab house and not blindly follow rules that may not be an issue.  Did you read the article?

Yes i read this article. But i can not insure that the first manufacturer will be the only one in product's life. Furthermoren in 90% i do not know in advance the manufacturer. So it is risky to assume that acid trap will not be a problem.

And it is easier/faster to avoid these geometry instead to have to argument whith persons in charge of checks: external design reviewer.  Each reviewer will have "his/her" demands. And each time manufacturer is changed, data are reviewed....

Glad you read it.
In our process flow, we require the board houses we work with to do a review of artwork we release to build.  We address all issues at feedback.  This acid trap acute angle has not been an issue since early 2000's.

An example of recent feedback from vendor: We just recently changed to a new fab house for a build an old board that used blue solder mask, they found that we were using 0.2mm clearance between openings (i.e. pins on fine pitch devices), this failed their DFM rules.

There has never have an issue at our organization with acute angles failing any of the vendors DFM rules and we have never had issues do to "Acid Traps" this century.

I agree it is good to be safe, you and your design staff following this rule does no harm. However I would hate to see  this to the community blindly following a person's opinion rather managing by fact.  So I advise all who take the time to read these posts do the engineering due diligence and investigate this issue on their on, and if you find any documents on this topic that suggest "acid traps" are an issue in 2021, I would be thankful for the feedback.

In Quality 101 (From a Deming award winning US manufacturer I worked for) - The story of my mother making a pot roast:  She always cut off 1 inch form the pot roast before she put it into an oven.  I asked her why she did this, she replied "That's how my mother did it".  I asked Grand Ma, why, she said "The butcher always cut the roast to 12 inches and my pan was 11 inches.  The take away was always to understand why we do things and not just blindly follow the process.  "Manage By Fact"

Kind Regards,

Wild