Finished planning for the upcoming bike trip, thanks to @bikerouter - works nicely also for Japan!
Doing this for the third year now. The planning with bikerouter improved. Distributing the routes to the 2 Android phone I'll use also works, via #syncthing, and then loading in OSMand.
Single routes of 130/31/44/117km.
Annoyingly, the company provided iphone which I'll use as backup: due to missing syncthing on ios, I'm like a cave man attaching the routes to a mail which I open on the phone..