Today I received a bug report from a user who thought CouchDB might be relaxing and evaluate an arithmetic expression in the config. (That makes sense, since it seems to evaluate erlang terms elsewhere.)
It would be nice for CouchDB to validate config input, particularly when bad values permanently take it offline. (In this case, it returns 500 for all subsequent requests.)
IMO, a good bang-for-buck is to have three basic value types:
2. Erlang tuple
And each setting knows what type it must be.