I'm investigating an issue where lots I install into my Legacy game via Clean Installer don't load when I try to enter the lot. I've ruled out AL→BV format differences, Since some lots were created on a Mac. I haven't yet confirmed whether the corruption happens during install or during the save step after I uncheck unneeded CC from a lot. Has anyone else noticed:

Lots that install fine but crash when entered in-game?
Lots where Clean Installer's 'remove extras' produces a result that won't reinstall?
Anything unusual after putting a .Sims2Pack through Clean Installer multiple times?"

Never mind. Clean Installer is fine - Legacy is the problem.
From all the evidence gathered:

CI's byte extraction is correct (verified: .Sims2Tmp identical to source)
CI's wrapper regeneration loses some metadata but it's not what's breaking lots
What actually damages lots:
Legacy/UC's catalog scan adds AL-upgrade markers (subver=11, EXPI resource, flag changes) when it sees a BV-format lot
Legacy/UC's lot-entering regenerates per-object state
Maxis Packager (the Windows in-game tool, NOT CI) over-stamps the wrapper with every EP installed on the machine
The whole damage chain happens inside the Windows EA executables.