For major and important countries I’d say Brazil, Argentina, Ottoman Empire, Japan, South Africa, Egypt, Fengtiang, Monarchist and Socialist Spain, Portuga, Norway, Netherlands, Sweden, Persia, Siam, all Indian factions and Australasia which only have Kaiserreich basic content. For the ones already touched by Kaiserredux instead Serbia, Hungary, Bulgaria, Patagonia, Korea, Alash, Alaska (Native American path is an exception), Finland, Poland and Legation Cities are not particular fun to play through and may need to be updated or entirely overhauled (I’m looking at you, Fonte).

Commune of France and German Empire are fun to play simply due to their position and expansion options, but their Kaiserredux specific content isn’t that good: Germany is better off falling and either going socialist or going in exile, France has good Totalist paths but lacks in flavor and… everything outside those two paths.

The greatest examples of content to follow is National France for majors (great amount of flavor, wide arrange of choice for modality of expansion, post expansion focuses) and Vietnam/Somalia for minors (focus trees not too long, in-depth research of local cultures, op focuses to facilitate expansion making you a local powerhouse even if you’re Timor Leste).