Author of https://www.taskbone.com/ here.
You are correct, that there is no two-way-sync with my plugin. To be more precise: You can push tasks into Todoist and you can pull tasks from Todoist. There is no way to push/pull updates, right now. But I am working on it.
Since everyone’s workflow is a little bit different, I am aiming for a high level of flexibility. Unfortunately, this makes a few things a little bit harder to achieve.
I have some ideas about how I could get close to support your specific workflow. I will try some things and get back to you in the next days. To be sure: Do you want one markdown file per task or one file per project?
@janpeeters, @friednslip How would your ideal workflow look like?