The Peabody is a norm referenced assessment so we need to be careful using the Peabody for multiple assessments overtime because that’s not what it is designed to do…
Back to your question though, yes there are concerns about a ceiling affect for a child that is about to age out of a norm referenced test.
By initial observation of a child, if you feel like their motor skills are delayed, the assessment would still provide meaningful information during the evaluation. If you think they will be borderline average with their skills, you might consider using a different assessment. So ultimately, it would be a judgement call for the physical therapist. For the exam, I don’t think they will create a lot of gray area for these concepts if they want you to choose an exam.