HYPP only runs in a (popular but identified and identifiable) set of QH bloodlines. The OP couldn't remember the QH sire's name when she posted but indicated she did have access to his information somewhere. Taking the random guess that he's Impressive bloodlines and a carrier is COMPLETELY RANDOM. And that the offspring is also a carrier?! Completely random guess. Just because he's a QH? Jeez. I used to ride APHA and we had a barn full of quarter horses. Not a one had Hypp. Not a one was Impressive breeding. There's a better chance her horse's sire is not a carrier than that he is.
And why shivers? Because the dam is a warmblood and some of warmbloods have shivers? Because Uniform is big? If shivers is even heritable? Another wild stab in the dark.
I don't advocate breeding horses known to pass on genetic defects but given the information posted here it's a WILD ASSUMPTION that this mare has known defects or that the offspring would be subject to a higher risk of generic flaws.