BridgeDB's handling of config files is non-persistent and uses an old-style class
Every time the process receives a SIGHUP, the configuration is reset to the settings within bridgedb.conf, which does not allow for methods within BridgeDB to make persistent configuration changes.
The Main.Conf() class is also an old-style class which does not inherit from object(). This makes it difficult and buggy to subclass.
The Conf.getstate() and Conf.setstate() methods do not exist, as with most other special methods, due to being an old-style class. The previous two methods make serialization impossible.
Having proper support for congurable log levels in BridgeDB will require being able to make persistent config changes, otherwise the log level will just be continually reset to WARNING everytime a SIGHUP comes in.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information