For anyone who stumbles across this later, here's a KiBot project file that will automatically export the JLCPCB-compatible BOM/CPL file:

https://gitlab.com/stavros/esp32-cnc/-/blob/master/project.k...

It does this from a field on each part in the schematic called "JLC" containing the part number. The only thing I'm unsure of is whether the "footprint" column needs to be edited manually later, though.