Mannymac, I think you are trying to figure out how to save CPU time and reduce latency by substituting 44.1K versions of your files, then when you're done, put the high res files back in, right?
I don't think that can be done within a single project, and duping all your work back and forth between projects will be impractical.
It might be better to just figure out how to reduce CPU by freezing* parts of your project while you work on other parts.
*In case you haven't come across this: The freeze feature allows you to temporarily bounce your track, including soft synths and effects, to reduce the amount of CPU power needed.