The seeds of the boom started before their term of office - there's been something of a snowball effect recently.
Public spending on education went steadily down from 2004 to 2014. I highly doubt that there has been any rebound since then. If anything, I expect PiS to have cut spending just like the last time they were in charge. The recent massive teacher layoffs confirm this. I doubt that tertiary education was spared. In any case, there has been no significant reform that would propel forward.
As for a boom, having PiS in charge has probably scared away foreign investment, just like the last time. Poland's practical pariah status within the EU is certainly not helping, nor is the constant stream of Euroskeptic sabre rattling. Foreign direct investment dropped from 14.3 billion dollars in 2014 to 11.4 billion dollars in 2016, less than its level in 2006. That's quite a drop. Investment property prices have rebounded only slightly. Less than I expected. Productivity has increased only slightly. Every source I've seen says growth has been "slow, but steady". Even those with the most hype.
The workforce is shrinking rapidly, and will continue to do so for at least the next ten years, but that will be largely offset by Ukrainian immigrants, as long as too many of them don't abscond to greener pastures. Brain drain remains a huge problem (why do you think they are bringing in IT engineers from India). Oddly, the only country in the world with a bigger brain-drain problem than Poland is India. First-worlders are not flocking to Poland. Poles abroad are not returning. The only uptick in immigration has been among the Ukrainians, and, to a much lesser extent, third-worlders looking for a back-door to the EU. Those crowds of expats and (non-Ukrainian) foreigners are just not there. The number of Indians, for example, has increased only 50% in the last four years. That's a lot less than I expected.
Overall, I see modest, but steady, growth, with long-standing problems remaining in some sectors, especially healthcare and education. Nothing like the "Great Leap Forward" you portray. And if PiS keeps up their Eurosceptic antics, there could be a "Great Leap Backward".
But your focus on "growth" and "change" is what's puzzling me. A four-year-old is growing and changing at a phenomenal rate compared to a forty-year-old, but it's going to be a long time before they can stand eye to eye. Same with Poland. It may be growing and changing faster than its rich neighbors to the west, but it's going to be a long time before they are playing in the same league, especially in terms of tertiary education.