What ill-effect? Just like microb, Phone, Conboy, Khweeteur, TwimGo, ...; Settings and Application Manager both properly support portrait mode now. "Force rotation" forces rotation on things which don't support it (yet), such as Conversations, Media Player etc. It is intended behaviour that Settings and HAM will rotate out-of-the-box (i.e. with "force rotation" off) with the CSSU.
Some applications which support portrait provide per-app settings as to whether or not they should be always landscape, always portrait or auto-rotate. Some don't.
Currently, neither Settings nor HAM do. Please file a bug if you think they should.