TSS progression through phases

So does tss have to trend upwards through different phases throughout the year. For example what if my tss is lower during a build phase than it was during a base phase.? The base phase tss will be gained though lower intensity but higher volume but during a build should I be aiming to match or increase tss with higher intensity?
I understand that the tss generated in each phase is of a different type so does each phase have to have a net increase on the last or should I treat each block individually?

TR Blog: Why is TSS reduced between phases?