I like to keep the original source file intact, at least until I'm ready to export the finished product.
That said, if disk space is really tight (why, when a 4TB Seagate from
B&H is under $100 shipped?), if the input file is "CaptureOne" you can save the output file to "new.CaptureOne". Then, once the processing is completed and (Very Important!) you have verified that the output file is not corrupted and looks the way you want, you can delete the old "CaptureOne" and rename the output file accordingly.
I still like to hang on to the original source until processing is complete and the recipient is happy with the final results. And then some.