I have a mid-2010 17" MacPro with two internal 1TB SSD drives, running Catalina.
My hope was that I might be able to figure out a way to make them work effectively as one by pointing the "Documents", "Pictures" or "Movies" main folders to wherever I have space, much in same way as you can by setting up preferences in, for example, an app like iTunes. Not being able to do so means I have one SSD drive almost full and the other largely empty.
My question is: Has anyone else found a way to organize files in such a way that the Mac treats the two internal SSD drives effectively as one?