The latest Windows build (main build + hotfix) of Editor on Fire has import/export functionality for the LLPLUS MIDI format in case anybody is interested in trying it.
https://ignition4.customsforge.com/eof
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Oh cool, thanks for doing that! I haven't gotten to properly test it yet (beyond just opening it and seeing the option for the LLPLUS export) but I'll make a note about it in the guide doc. The midi structure will be getting updated in the next update to also be able to encode animations, but that's just adding new note bindings for animations, without changing the old ones, so all old maps will still work, so this will still work too without any changes.