There’s a new version 0.6.0, that goes back to the original implementation of column resizing – the one in prosemirror-tables. Keeping sections, of course.
Going back to that implementation should solve the problems in column widths at table creation and copy-paste.
It’s also a cleaner implementation, that should ease the task of people looking at the code of both prosemirror-tables and prosemirror-tables-sections.