Giedroyć doctrine was pursued by all the governments since 1989, even if the society as a whole wasn't always entirely persuaded.

For one example Poland accepted all the borders around it after WW2 the instant any country appeared (it was usually the first or 2nd country in the world recognizing each of these countries as they appeared). And renounced any territorial disputes. That's despite the fact before the war Vilnius and Lviv were top 5 Polish cities with huge cultural impact, and despite the fact that Poland lost 1/7th of it's territory after WW2 (even including the territory we got on the west as "compensation"). I will admit we got better land in exchange for marches and forests. But millions of people who got forcibly relocated after WW2 could be much more unreasonable about it than they were.

I agree German society is more reasonable about it than Polish society, but when it comes to elites - it was the opposite for a long time. German eastern policy was much more imperial than Polish one at least till 2021. They tended to ignore EE countries issues over appeasing Russia, treating all the problematic stuff as "russophobia" and dealing with Russia over the heads of the smaller countries (Nord Stream 1 and 2 is just one example, there were also the issues of Russia hacking Estonian elections, blocking the gas deliveries against the contract on purpose to blackmail EE countries, etc.) Germany was ignoring these for the longest time.

Also - Germans waited with recognizing Polish post-WW2 borders and only did it when they were forced to - to get unification accepted. It was surprisingly realpolitik. Similarly - to this day Germany does not provide most Slavic minorities with minority rights despite Germans enjoying German city names, street names, education in these languages, etc in German-speaking Polish regions. It's very weird when you compare the treatment of minorities in practice with the sentiments of the population and the stereotypes about the countries.

So I wouldn't single out Germany as the most reasonable politically regarding EE. Their political instincts were till the last few years to deal with Russia and ignore the small countries.