for our offline maps tool we use *.osm.pbf data for input. As we often need cross border selections or just a country with some "buffer" around borders we use cropped osm data using osmctools.
osmconvert europe-latest.osm.pbf -B=CH_border_buffer10km_v2.poly --complete-ways -o=Switzerland_custom_buffer.osm.pbf
However the resulting map has some features missing:
most apparent is the missing Bodensee - compared with online OSM layer provided by Terrestris:
Can I somehow solve this so the cropped data does not remove all features overlapping the trimline?
The resulting format however has to be osm.pbf. I found a mention of "--complete-multipolygons" parameter here, but osmctools (0.6-1 from ubuntu repository) does not offer me this.