Um snug? rule of thumb for oil filters in general is just snug really you don't want to "hurc" most stuff anyway especially something that's technically plastic lol

However certain things should be tightened with a torque wrench to specification for a lot of different reasons. I don't think an oil filter cap is one of them fools folly or not experience is worth more than anything you can a read in a book.

"Looks good on paper"