NPB, your best bet is BBM. Opening Day is March 30.
KBO, SCC is the only option. Opening Day is April 1.
Unfortunately, the Australian Baseball League doesn't consistently put out a yearly set. A few of the teams produce team sets, but that's about it. Their season just ended in January, and the 2023-24 season won't start until November.
Czech Extraliga's current season ends in a couple of weeks, and won't start again until October. I literally just learned they have cards because of your question. https://legendary-cards.cz/c26-baseball I will investigate further and try to get them listed here.
The Cuban National Series (Serie Nacional de Béisbol) also doesn't have a regular set of cards. Like most Caribbean leagues, they run during the winter months, so their season ended in January.
Other pro leagues include the CPBL in Taiwan, they usually have a set of cards issued by the league, but they are always a season or two behind. Honkbal Hoofdklasse is the pro league in the Netherlands. I've seen a few individual team sets, but never a league-wide set.