Hello,
According to manual (both Baltic Dragon's one and real flight manual) speed brake switch should stay in selected position, and speed brake should stop raising or retraction in middle (hold) position. In DCS F15E when using HOTAS binds "speed brake step aft" and "speed brake step fwd" it's not possible to put switch to HOLD position. It's only possible if I had a 3-position switch irl and then using speed brake AFT and speed brake FWD binds.