SingleThreadDecay:
I would say the preffered setting is True. In former days or without this setting active each realm has a dedicated thread with the only purpose to iterate over the complete map to find items to destroy. With this setting active it's only one thread for all realms.
ThreadDecayStatistics:
(Only used with above setting also set)
Since iterating over the complete world to find items to destroy is really a big overhead the story is not over. I added this setting to print statistics per run how many items are able to decay currently and how many items got destroyed to find the best implementation. I hope I will find time again to finish this todo. I would be glad if any shardowner who reads this activates this for a few days and sends me the log prints.
WarmodeInhibitsRegen:
Yes name is selfexplaining without other side effects (oh my god)
DebugLevel:
The current highest level is 22. All of them pretty senseless if you don't search a bug somewhere near these lines. Search for INFO_PRINT_TRACE in the sources to find the spots and what they print.
WatchRPM:
The tachometer "rotations per minute" prints some informations how busy the script scheduler was
WatchMapCache:
I guess this is a left over, atleast the variables which get printed never change, plus our map is completely in RAM there cannot be a cache miss.