The thing is is that punched cartos come with 1 to 3 holes, and I have even seen some with slots, depending on the maker and the liquid, you may or may not need more holes. I use smoketech dual coil carto's with one or two holes and never had to punch extra holes if I vape a 100% pg liquid.
If I vape a 100% vg liquid, I will punch a couple of extra holes. But, that is very easy to do. Most places that sale tanks sale simple hole punchers for less the $8 that are easy for even an elderly arthritic half blind old lady like myself to use and punch a couple of extra holes in less then a minute. And yes, they work well with an ego twist -