tilekit -export input_file.tkp output_file.json
Yup, that's exactly it. Thanks!
Truthfully, the border-1-vs-padding-2 might have been from an early, unfortunate config of Texture Packer. It just so happens that my tileset in my game used it and some code is written to support it... but, really, not needed. I withdraw the request. :)
I appreciate the minimal config surface of Tilekit and would rather it remain simpler and opinionated and good, so I can appreciate your dilemma. Thanks for considering it.