Strange brake behavior with notched train brake + air loco brake

With this combination, there's no dynamic braking on the train, loco brake handle sounds don't play (aren't these supposed to be a separate sound.cfg entry btw?) and it affects train brakes (applies air brakes briefly on the whole train when using loco brake) regardless of Type setting. Tested on April 6 build

Also, when notched loco brake is applied on the locomotive (= consist where only car 0 is powered), speed falls below BrakeControlSpeed and it switches to air brakes, brake release sound plays.