The param editor isn't completely perfect. Due to the way the game handles it's param files, it's closet to impossible to fully rebuild certain files. Namely, files with embedded groups (groups inside of groups). The game has a function to parse params specific to the param file being parsed. Meaning that there isn't a generic way to parse them, as far as i know of at least. Though some break, I'd say 80% of the param files work fine. Unfortunately that happens to be one of them. Bayonetta's char specific param_vl file is also one of them.
Were you using the beta version of sm4shcommand? Or at least the events.cfg from then beta or the repository? If you don't use the newer events.cfg files then the game will crash on certain moves and cause weird issues.
I am using the latest version. Any other older version crashes when trying to extract or repack dt and ls for european versions.