In part, that could be because you're focused on TT power, whereas it is short-term power that it really impacted by how "fresh" you are. For example, there's a study soon to be published in Med Sci Sports Exerc showing that even doing intervals the morning before followed by 2 h of tempo the afternoon before only slowed cyclists by 1 min in a simulated 40 km TT compared to when they were fully rested. When you consider studies like this one (or frequency distributions of TSB at time of a power PB for shorter vs. longer durations), it really becomes rather worrisome that the impulse-response model (upon which the PMC is based, and as fully implemented in RaceDay) has never been validated using a performance test longer than 5 min in duration. But, these are probably more thoughts that are going to be lost on 99.99% of people...