Lots install fine, but some CC (even non-store content) does not. I d/l some lipsticks and had to convert them to .package format, b/c Launcher couldn`t do the job. Could it somehow be connected to .s3p format files created with an older version of TSR Workshop?
It is possible, but you know you can get the launcher to install things(including store items) simply by replacing the TS3EP01.exe or TS3.exe with an .exe that is a version from before the latest 2.3 or 1.8 patch and then just putting the patched version back before you play. There is an entire thread on that ...although frankly, it seems to me as if it's making the process overly complicated, or using a lot of directions for a simple process, I actually stopped reading once I put together that it was only the .exe that was necessary.
Anyway, to answer your question, couldn't you use the 3Viewer or Delphy's Sims 3 Pack Multi-Extracter to extract the .package file and then just drop that in the appropriate folder, which for lots would be the Library folder.