This is intriguing... (at least to me).
I was showing a friend of mine, who is interested in exploring Sotos' work, the scans that I and others have made, and I noticed that tool. was altered for its inclusion in Proxy. The order of chapters is different, and I noticed that the very beginning of my favorite chapter, the letter, starts with "My Dear Woman" in Total Abuse and the standalone publication and "Mrs. Anderson" in Proxy. I wonder why this (or any) alterations are made to the text(s) after the fact.
Furthermore, I wonder what, if any, changes were made to his other works that were later republished in collections. Hmm...