Sorry if I'm missing something obvious here. The following questions both reference the InstallExecuteSequence table:
http://stackoverflow.com/questions/1178327/force-reboot-from-custom-action-in-msi-in-c
http://stackoverflow.com/questions/3404288/msi-installer-to-run-twice
And here's the MS page:
http://msdn.microsoft.com/en-us/library/aa369500%28VS.85%29.aspx
There's lots of information about this and using the installer database lying around, but what I can't find is how is the InstallExecuteSequence Table modified? Or how anything in the installer database is modified? What actual steps, files, modules or options need to be changed and where are they located?