GPS Babel maybe. It's not the most user-friendly but very powerful https://www.gpsbabel.org/htmldoc-1.5.4/filter_track.html
Won't split without a time.
" the track filter requires timestamps on all trackpoints"
You can add fake timestamps using gpsbabel but I've no idea whether that's a good idea.
@hippy started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
GPS Babel maybe. It's not the most user-friendly but very powerful https://www.gpsbabel.org/htmldoc-1.5.4/filter_track.html