Hi.
I'm thinking about better tagging for different services and finally choose "service:name" which can be localized in standard way.
Local train routes in Japan often too short to classify as regional.

Hi.
There is one station of one operator with common numbering of platforms. Even officially https://subway.city.fukuoka.lg.jp/eki/stations/hakata.php .
Big stations can have such layout - Osaka and Tokyo for example.
By the way when mapping as two stations users may start search exit from one and entrance to another.

but this is single station and transfer inside it