Testing the ATUM plugin against our 500+ product inventory is essential before we can use it in production. We need to manage inventory from multiple locations so import and exporting will be critical.
In your support forum, at the time we purchased 2 weeks ago, someone posted they were able to successfully import and export with WP All Import and WP All Export. One user even provided sample code to use. That has since been removed from the forum or I can no longer find it. Also at the time, your import/export add on was not available.
I understand you're selling the addon capability and have no problem paying full price but we want to see if it works for us. I hope you could understand the time involved with that?