I personally work a lot with Org mode, but collaborate on bigger projects with other people through proprietary tools. Some of them are very good for collaboration like Pivotal Tracker. So it totally makes sense to use them in heterogeneous teams! In fact, very often it is me introducing them into the team.

However, for my workflow (which is based on GTD) it is important to know that I have all my pending tasks visible in one place. In fact, that's one of the great features of Org mode - I have my meeting minutes, tasks with links to resources like mails, time tracking, etc, all in one place. Having some tasks scattered in different tools is dangerous, because:

• It's easy to forget tasks in some tracker
• It's not easy to have an overview of everything that's pending and quickly create a ranking of importance
• It creates mental overhead

For this reason, I import tasks from proprietary tools into my local Org mode agenda. I don't do anything fancy with it like two-way sync as this complicates matters a lot. Those external tools are great at what they do (collaboration [potentially in real time], exchanging assets, etc) and there is little sense to clone that functionality in Emacs. There's more important things to do, at least^^

My flow is:

• I have a cronjob running every 15 minutes retrieving tasks from external sources
• It creates a file readable in my local agenda
• When this file has changed since the last run (checked with =git=), I'll get a desktop notification (through =notify-send=).

For importing tasks from Pivotal Tracker, I just open sourced my small script which you can find here: https://gitlab.com/200ok/tracker2org

It's nothing fancy, at all, but it might save you the time to write it yourself. Or you might just take the thought away that it might make sense to have a local copy of all the (potentially distributed) tasks.