Just wanted to ask you, why you're not creating the actions you need and create a backup of everything using the method outlined at Documentation → Exporting and importing preferences settings?
This would certainly address the
I'm intentionally not documenting the internal file format of MTA actions, because it would require me to also update this documentation whenever I change something internally.
In addition, as @ohrenkino already pointed out, manually adapting those often introduces errors that can only be solved after users are contacting me via email and asking why their action produces an error message.
If you have other reasons for needing information on this implementation detail, please let me know.