It is the responsibility of the applicant, or any subsequent developer, to ensure that the requirements of all conditions are met in full. Any conditions that need to be discharged should be discharged at the relevant time.
But the appeal process can take up to six months, and you can’t start building work during that time. And because the Planning Inspector will examine the whole of your original planning application, you can lose your planning permission altogether.
Failure to discharge conditions before commencing development could result in the development being unlawful or enforcement action being taken.