Testing PBNs

What is your opinion about testing your expired domains before adding to your network?

The test itself is described here diggitymarketing.com/how-to-test-your-pbns/

I was thinking that if you are trying to rank a site, you add tens of backlinks each month. In such a case it is hard to say if this particular PBN link actually works or not.

Since PBNs are supposed to be one of the most powerful links you get, you gotta make sure they work properly, correct?