This doesn't cover the use-case of having unique info in both at the same time, allowing you to paste in your desired order. I have a script where I read from t

This doesn't cover the use-case of having unique info in both at the same time, allowing you to paste in your desired order. I have a script where I read from the primary selection, modify the text, and put it on the clipboard. I use this along with something more like a regular clipboard manager to complete a task. Combined I can highlight some text, put other info on my main clipboard to paste right away, then run my script that uses the primary selection afterward without going back to re-copy the first text.