Yeah, I did a crap job of labeling those things in the BOM. They just inherited their part names - but aren’t really tied to what you need to do. That is up to you. Just look at the number of pins, rows and gender.
I made the initial test TXo with standard headers all around. For the production run, I switched the board interconnects to precision headers (including the teensy one). This slimmed the module. You can also just solder the boards together and skip the female headers, but this makes makes it hard to troubleshoot.
If you need more help from here, I can go through and improve the list in the BOM. Might take me a couple days to get to it…
BTW: excited to see someone else building them!!!