It can be annoying to need to move privdata values around when moving services between hosts, which is otherwise often just a cut-n-paste of a line in config.hs.
It would be better if privdata were all stored in one Map, and the set of privdata that a host's current properties need were sent to it automatically, rather than the current 1-file-per-host separation.
For this to work though, each property that uses privdata would need to add to the host's Info the privdata field it uses.