Custom xAPI Statements published with TinCan

Hello! I'm hoping someone can provide some insight on using custom xAPI statements along with Storyline's out of the box statements when publishing to TinCan. I've been successful in using my own custom xAPI statements that report back to an LRS when I publish to web, but ultimately I want to publish to TinCan so I can upload the course to our LMS. This is where I run into problems. When I publish to TinCan and upload to our LMS, my custom statements are being completely ignored, and only Storyline's out of the box statements are being reported to the LRS within our LMS. Ultimately my goal is 1) to be able to upload the course to our LMS and 2) have the xAPI statements (at least my custom statements) report out to an external LRS. I've read other documentation and posts that seem to suggest this is possible but no one ever explains how this can be accomplished. I understand that every LMS is different, but my big question is what can I do to my custom statements so that report back to the LRS along with the default statements? 

***I'll add I have read that Storyline 360 recently added additional enhancements for xAPI, but I am currently using Storyline 3.***