Crincit I noticed the tmp files when I installed the latest store venue by my launcher. I have bypassed the launcher for quite awhile by using the TSW3 exe. I deleted the temp files and continue to use the exe and have no notice of missing files. Just wanted to add another data point.
Edit: Wanted to add when I saw the new tmp files I started a clean folder and copied over the DCCache, Library and Installed Worlds folders and the ccmerge.package into the DCBackup folder. (I have a separate folder that I just use for store installs through the launcher). I deleted all the tmp files from the DCCache folder. Once I compied my save folder, I was able to play old saves without any problems.