First off I’m glad you found my posts helpful! When I get to 88% or 89% its time for more vo2 work! Coach Chad covered this in a deep dive:
WKO modeling relies on an accurate power duration curve. And even then models are models, so its not perfect but can give a good or very good estimate depending on the model. Feeding the model with good max efforts every 4-6 weeks is necessary to get good estimates from the model. Post any WKO questions in another thread!