Hi. @JonMakesBeats, welcome to Elektronauts. I hope you got what I meant. Please post more on Elektronauts ! 
Check this :
Elektronauts Hiphop Beat Battle #15: Into The Sunset— Morricone edition
(You can set notifications if interested)
Concerning projects, I lazily used one project per “musical project” before. When my full 16GB card went wrong probably because I turned off OT too quickly while being writing, I had to think about it. A saved project without samples in its folder is around 20MB iirc. Btw there is an option to save recordings in active project.
AFAIK, concerning projects between 2 OTs with the same card data, the only difference beside hardware can be settings in PERSONALIZE menu, and it shouldn’t affect playback.
Beside that, the “only?” difference between projects can be sample assignments : you can copy a bank from project A to project B, it will copy patterns and parts (both are written in bank files), or copy patterns and their parts individually. But sample slots have to correspond.
You can write project A sample slots allocation on reliable hardware (paper 
), and change them one by one to match them on project B. It is also possible to modify the project file, but projects have to be in the same SET (a Set is just a folder, but you can’t play samples from a different Set).
Sample path example, you can edit it with a text editor :
Transferring songs from old Octatrack to the new one - #8 by sezare56
Another thing to know is that saved files (.strd files, created after SAVE) and current files (.work) are different. I’d edit project.work file, then save project (or copy and change extension .work to .strd).