Blocking the EGR Valve

[the evil twin]

Does the CRD EGR blanking plate need a hole in it? I thought I'd read somewhere it did

A small hole will stop the ECU throwing occasional P0401 fault codes (EGR Volume error).

I didn't drill mine tho.
Every CRD owner should have a scanner, crazy if you don't IMHO, so all you do is reset the fault on the rare occasions you happen to get them.