just been working on some updates for chunks based plugins. I never really needed to use chunks before and was always getting confused between the various Serialize/UnSerialize methods (which ones to override, possibly due to problems in the original implementation)
I think I have reworked it a nice way now (but need to test some more and make sure I didn't break anything). The IPlugChunks example seems to work.
https://github.com/olilarkin/wdl-ol/tree/chunks
basically now you only ever override SerializeState / UnserializeState if using chunks, making sure to call IPlugBase::SerializeParams() / IPlugBase::UnserializeParams() at the end of the method.