installed exe disappears during uninstall before it can clean up

I’m trying to get the uninstall of a qt-ifw based installer to call an exe (which was installed via that installer) for some rather complex system-specific stuff that that exe has to perform for install and uninstall (e.g. device management, windows system api calls). I tried to do that by adding an “Execute” operation with addElevatedOperation, but that turned out to fail more often than not.

Most of the time, it looks as if the exe was already deleted before that operation is called.
Indeed, the qtifw doc page about operations says “Note: Operations are performed threaded.” which might explain that the file deletion might sometimes come before the execute operation. On the other hand, i see no way to control/synchronize the uninstallation operations so as to insure that that execute operation is finished before the exe is deleted, nor any other way to call that exe at the beginning of the uninstallation.

I must be missing something here. So how can i get the uninstaller to call that exe before it deletes it?