You would like to produce a sheet with a large amount of holes. Sheet distortion results due to the small hole spacing. There is no patent solution for it. BUT: there are some countermeasures!

Fundamentally you should keep in mind that:

• you make the right choice for clearance
• you should use only sharp / ground tools
• use an active stripper or fully guided cluster punch

Should all of these points not be enough, there is the option to use tools that release sheet stress and warping.
In this case there are toolings with convex surface:

Stripper is produced concave
(Attention: use only active stripper)

Influence:
On each hit the sheet will be pretensioned and adjusted against the usual emboss.