"certain enough" is correct and usable in written English. It generally means that something is certain or definite. For example, "The weather report says it's supposed to snow tomorrow - certain enough for me to buy a new coat!".
Those details, at least, seem certain enough.
The company said it was no longer certain enough of its outlook to provide earnings guidance for the year.
As Bree struggles to decide if she's certain enough to make a life with Lara over her conservative family's objections, the complications of her situation ring true.
In 1884, Abraham Vanderbeck, a meat dealer, was certain enough of the value of his house, No. 151, to add the unusual mansard roof.
"At a certain point, enough is enough and somebody has to say something," Watts said.
Except that, for certain chefs, enough is never enough.
Chapala, which hit southern Yemen with exceptional intensity on November 3, left close to 200mm of rain in certain areas, enough to possibly keep the soil moist enough for female locust to deposit eggs for six months, said Cressman.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com