[Blind-sysadmins] ddwrt, shortcut forwarding engine, and bluetooth coexistence mode?

Hello, To any users of dd-wrt v24 3.x recent builds. I've got two options i'm not sure of and searching makes me more confused. The first, which is enabled is shortcut forwarding engine. The second which is disabled for both 2.4 and 5Ghz networks is bluetooth coexistence. Impressions appreciated. Thanks. Dave.