Most of the extensions I installed in PPI were thankfully PPI compatible. Some can be made to be PPI compatible, if they don't include files that have to install into /usr/share, /etc...for example, executables installed to /usr/bin can usually simply be moved to /usr/local/bin. Libraries can often be handled the same way. For compiletc, I ended up putting as much of it into /usr/local as possible, including moving some executables and libs, and then made a new tce package from the remaining files (basically te same as putting them in a backup as Jason recommended). I still have a couple of modules that I want to try to convert to PPI-compatible packages, but for now I'm just loading them from tce.